src/HOL/Groups.thy
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(*  Title:   HOL/Groups.thy
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    Author:  Gertrud Bauer, Steven Obua, Lawrence C Paulson, Markus Wenzel, Jeremy Avigad
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*)
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header {* Groups, also combined with orderings *}
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theory Groups
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imports Orderings
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begin
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subsection {* Fact collections *}
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ML {*
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structure Ac_Simps = Named_Thms
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(
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  val name = @{binding ac_simps}
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  val description = "associativity and commutativity simplification rules"
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)
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*}
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setup Ac_Simps.setup
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text{* The rewrites accumulated in @{text algebra_simps} deal with the
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classical algebraic structures of groups, rings and family. They simplify
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terms by multiplying everything out (in case of a ring) and bringing sums and
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products into a canonical form (by ordered rewriting). As a result it decides
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group and ring equalities but also helps with inequalities.
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Of course it also works for fields, but it knows nothing about multiplicative
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inverses or division. This is catered for by @{text field_simps}. *}
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ML {*
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structure Algebra_Simps = Named_Thms
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(
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  val name = @{binding algebra_simps}
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  val description = "algebra simplification rules"
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)
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*}
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setup Algebra_Simps.setup
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text{* Lemmas @{text field_simps} multiply with denominators in (in)equations
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if they can be proved to be non-zero (for equations) or positive/negative
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(for inequations). Can be too aggressive and is therefore separate from the
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more benign @{text algebra_simps}. *}
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ML {*
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structure Field_Simps = Named_Thms
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(
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  val name = @{binding field_simps}
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  val description = "algebra simplification rules for fields"
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)
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*}
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setup Field_Simps.setup
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subsection {* Abstract structures *}
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text {*
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  These locales provide basic structures for interpretation into
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  bigger structures;  extensions require careful thinking, otherwise
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  undesired effects may occur due to interpretation.
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*}
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locale semigroup =
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  fixes f :: "'a \<Rightarrow> 'a \<Rightarrow> 'a" (infixl "*" 70)
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  assumes assoc [ac_simps]: "a * b * c = a * (b * c)"
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locale abel_semigroup = semigroup +
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  assumes commute [ac_simps]: "a * b = b * a"
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begin
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lemma left_commute [ac_simps]:
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  "b * (a * c) = a * (b * c)"
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proof -
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  have "(b * a) * c = (a * b) * c"
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    by (simp only: commute)
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  then show ?thesis
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    by (simp only: assoc)
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qed
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end
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locale monoid = semigroup +
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  fixes z :: 'a ("1")
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  assumes left_neutral [simp]: "1 * a = a"
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  assumes right_neutral [simp]: "a * 1 = a"
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locale comm_monoid = abel_semigroup +
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  fixes z :: 'a ("1")
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  assumes comm_neutral: "a * 1 = a"
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begin
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sublocale monoid
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  by default (simp_all add: commute comm_neutral)
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end
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subsection {* Generic operations *}
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class zero = 
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  fixes zero :: 'a  ("0")
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class one =
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  fixes one  :: 'a  ("1")
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hide_const (open) zero one
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lemma Let_0 [simp]: "Let 0 f = f 0"
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  unfolding Let_def ..
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lemma Let_1 [simp]: "Let 1 f = f 1"
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  unfolding Let_def ..
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setup {*
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  Reorient_Proc.add
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    (fn Const(@{const_name Groups.zero}, _) => true
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      | Const(@{const_name Groups.one}, _) => true
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      | _ => false)
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*}
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simproc_setup reorient_zero ("0 = x") = Reorient_Proc.proc
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simproc_setup reorient_one ("1 = x") = Reorient_Proc.proc
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typed_print_translation {*
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  let
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    fun tr' c = (c, fn ctxt => fn T => fn ts =>
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      if null ts andalso Printer.type_emphasis ctxt T then
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        Syntax.const @{syntax_const "_constrain"} $ Syntax.const c $
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          Syntax_Phases.term_of_typ ctxt T
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      else raise Match);
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  in map tr' [@{const_syntax Groups.one}, @{const_syntax Groups.zero}] end;
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*} -- {* show types that are presumably too general *}
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class plus =
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  fixes plus :: "'a \<Rightarrow> 'a \<Rightarrow> 'a"  (infixl "+" 65)
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class minus =
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  fixes minus :: "'a \<Rightarrow> 'a \<Rightarrow> 'a"  (infixl "-" 65)
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class uminus =
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  fixes uminus :: "'a \<Rightarrow> 'a"  ("- _" [81] 80)
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class times =
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  fixes times :: "'a \<Rightarrow> 'a \<Rightarrow> 'a"  (infixl "*" 70)
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subsection {* Semigroups and Monoids *}
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class semigroup_add = plus +
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  assumes add_assoc [algebra_simps, field_simps]: "(a + b) + c = a + (b + c)"
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begin
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sublocale add!: semigroup plus
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  by default (fact add_assoc)
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end
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class ab_semigroup_add = semigroup_add +
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  assumes add_commute [algebra_simps, field_simps]: "a + b = b + a"
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begin
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sublocale add!: abel_semigroup plus
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  by default (fact add_commute)
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lemmas add_left_commute [algebra_simps, field_simps] = add.left_commute
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theorems add_ac = add_assoc add_commute add_left_commute
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end
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theorems add_ac = add_assoc add_commute add_left_commute
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class semigroup_mult = times +
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  assumes mult_assoc [algebra_simps, field_simps]: "(a * b) * c = a * (b * c)"
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begin
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sublocale mult!: semigroup times
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  by default (fact mult_assoc)
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end
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class ab_semigroup_mult = semigroup_mult +
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  assumes mult_commute [algebra_simps, field_simps]: "a * b = b * a"
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begin
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sublocale mult!: abel_semigroup times
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  by default (fact mult_commute)
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lemmas mult_left_commute [algebra_simps, field_simps] = mult.left_commute
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theorems mult_ac = mult_assoc mult_commute mult_left_commute
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end
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theorems mult_ac = mult_assoc mult_commute mult_left_commute
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class monoid_add = zero + semigroup_add +
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  assumes add_0_left: "0 + a = a"
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    and add_0_right: "a + 0 = a"
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begin
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sublocale add!: monoid plus 0
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  by default (fact add_0_left add_0_right)+
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end
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lemma zero_reorient: "0 = x \<longleftrightarrow> x = 0"
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  by (fact eq_commute)
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class comm_monoid_add = zero + ab_semigroup_add +
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  assumes add_0: "0 + a = a"
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begin
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sublocale add!: comm_monoid plus 0
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  by default (insert add_0, simp add: ac_simps)
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subclass monoid_add
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  by default (fact add.left_neutral add.right_neutral)+
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end
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class comm_monoid_diff = comm_monoid_add + minus +
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  assumes diff_zero [simp]: "a - 0 = a"
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    and zero_diff [simp]: "0 - a = 0"
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    and add_diff_cancel_left [simp]: "(c + a) - (c + b) = a - b"
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    and diff_diff_add: "a - b - c = a - (b + c)"
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begin
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lemma add_diff_cancel_right [simp]:
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  "(a + c) - (b + c) = a - b"
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  using add_diff_cancel_left [symmetric] by (simp add: add.commute)
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lemma add_diff_cancel_left' [simp]:
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  "(b + a) - b = a"
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proof -
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  have "(b + a) - (b + 0) = a" by (simp only: add_diff_cancel_left diff_zero)
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  then show ?thesis by simp
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qed
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lemma add_diff_cancel_right' [simp]:
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  "(a + b) - b = a"
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  using add_diff_cancel_left' [symmetric] by (simp add: add.commute)
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lemma diff_add_zero [simp]:
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  "a - (a + b) = 0"
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proof -
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  have "a - (a + b) = (a + 0) - (a + b)" by simp
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  also have "\<dots> = 0" by (simp only: add_diff_cancel_left zero_diff)
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  finally show ?thesis .
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qed
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lemma diff_cancel [simp]:
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  "a - a = 0"
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proof -
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  have "(a + 0) - (a + 0) = 0" by (simp only: add_diff_cancel_left diff_zero)
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  then show ?thesis by simp
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qed
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lemma diff_right_commute:
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  "a - c - b = a - b - c"
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  by (simp add: diff_diff_add add.commute)
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lemma add_implies_diff:
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  assumes "c + b = a"
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  shows "c = a - b"
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proof -
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  from assms have "(b + c) - (b + 0) = a - b" by (simp add: add.commute)
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  then show "c = a - b" by simp
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qed
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end
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class monoid_mult = one + semigroup_mult +
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  assumes mult_1_left: "1 * a  = a"
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    and mult_1_right: "a * 1 = a"
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begin
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sublocale mult!: monoid times 1
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  by default (fact mult_1_left mult_1_right)+
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end
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lemma one_reorient: "1 = x \<longleftrightarrow> x = 1"
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  by (fact eq_commute)
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class comm_monoid_mult = one + ab_semigroup_mult +
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  assumes mult_1: "1 * a = a"
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begin
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sublocale mult!: comm_monoid times 1
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  by default (insert mult_1, simp add: ac_simps)
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subclass monoid_mult
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  by default (fact mult.left_neutral mult.right_neutral)+
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end
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class cancel_semigroup_add = semigroup_add +
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  assumes add_left_imp_eq: "a + b = a + c \<Longrightarrow> b = c"
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  assumes add_right_imp_eq: "b + a = c + a \<Longrightarrow> b = c"
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begin
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parents: 27250
diff changeset
   305
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   306
lemma add_left_cancel [simp]:
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   307
  "a + b = a + c \<longleftrightarrow> b = c"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   308
by (blast dest: add_left_imp_eq)
27474
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   309
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   310
lemma add_right_cancel [simp]:
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   311
  "b + a = c + a \<longleftrightarrow> b = c"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   312
by (blast dest: add_right_imp_eq)
27474
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   313
a89d755b029d move proofs of add_left_cancel and add_right_cancel into the correct locale
huffman
parents: 27250
diff changeset
   314
end
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   315
22390
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   316
class cancel_ab_semigroup_add = ab_semigroup_add +
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   317
  assumes add_imp_eq: "a + b = a + c \<Longrightarrow> b = c"
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   318
begin
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   319
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   320
subclass cancel_semigroup_add
28823
dcbef866c9e2 tuned unfold_locales invocation
haftmann
parents: 28262
diff changeset
   321
proof
22390
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   322
  fix a b c :: 'a
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   323
  assume "a + b = a + c" 
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   324
  then show "b = c" by (rule add_imp_eq)
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   325
next
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   326
  fix a b c :: 'a
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   327
  assume "b + a = c + a"
22390
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   328
  then have "a + b = a + c" by (simp only: add_commute)
378f34b1e380 now using "class"
haftmann
parents: 21382
diff changeset
   329
  then show "b = c" by (rule add_imp_eq)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   330
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   331
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   332
end
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   333
29904
856f16a3b436 add class cancel_comm_monoid_add
huffman
parents: 29886
diff changeset
   334
class cancel_comm_monoid_add = cancel_ab_semigroup_add + comm_monoid_add
856f16a3b436 add class cancel_comm_monoid_add
huffman
parents: 29886
diff changeset
   335
856f16a3b436 add class cancel_comm_monoid_add
huffman
parents: 29886
diff changeset
   336
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   337
subsection {* Groups *}
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   338
25762
c03e9d04b3e4 splitted class uminus from class minus
haftmann
parents: 25613
diff changeset
   339
class group_add = minus + uminus + monoid_add +
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   340
  assumes left_minus [simp]: "- a + a = 0"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   341
  assumes add_uminus_conv_diff [simp]: "a + (- b) = a - b"
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   342
begin
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   343
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   344
lemma diff_conv_add_uminus:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   345
  "a - b = a + (- b)"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   346
  by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   347
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   348
lemma minus_unique:
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   349
  assumes "a + b = 0" shows "- a = b"
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   350
proof -
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   351
  have "- a = - a + (a + b)" using assms by simp
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   352
  also have "\<dots> = b" by (simp add: add_assoc [symmetric])
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   353
  finally show ?thesis .
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   354
qed
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   355
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   356
lemma minus_zero [simp]: "- 0 = 0"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   357
proof -
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   358
  have "0 + 0 = 0" by (rule add_0_right)
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   359
  thus "- 0 = 0" by (rule minus_unique)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   360
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   361
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   362
lemma minus_minus [simp]: "- (- a) = a"
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   363
proof -
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   364
  have "- a + a = 0" by (rule left_minus)
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   365
  thus "- (- a) = a" by (rule minus_unique)
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   366
qed
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   367
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   368
lemma right_minus: "a + - a = 0"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   369
proof -
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   370
  have "a + - a = - (- a) + - a" by simp
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   371
  also have "\<dots> = 0" by (rule left_minus)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   372
  finally show ?thesis .
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   373
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   374
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   375
lemma diff_self [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   376
  "a - a = 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   377
  using right_minus [of a] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   378
40368
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   379
subclass cancel_semigroup_add
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   380
proof
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   381
  fix a b c :: 'a
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   382
  assume "a + b = a + c"
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   383
  then have "- a + a + b = - a + a + c"
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   384
    unfolding add_assoc by simp
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   385
  then show "b = c" by simp
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   386
next
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   387
  fix a b c :: 'a
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   388
  assume "b + a = c + a"
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   389
  then have "b + a + - a = c + a  + - a" by simp
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   390
  then show "b = c" unfolding add_assoc by simp
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   391
qed
47c186c8577d added class relation group_add < cancel_semigroup_add
haftmann
parents: 39134
diff changeset
   392
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   393
lemma minus_add_cancel [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   394
  "- a + (a + b) = b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   395
  by (simp add: add_assoc [symmetric])
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   396
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   397
lemma add_minus_cancel [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   398
  "a + (- a + b) = b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   399
  by (simp add: add_assoc [symmetric])
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   400
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   401
lemma diff_add_cancel [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   402
  "a - b + b = a"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   403
  by (simp only: diff_conv_add_uminus add_assoc) simp
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   404
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   405
lemma add_diff_cancel [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   406
  "a + b - b = a"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   407
  by (simp only: diff_conv_add_uminus add_assoc) simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   408
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   409
lemma minus_add:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   410
  "- (a + b) = - b + - a"
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   411
proof -
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   412
  have "(a + b) + (- b + - a) = 0"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   413
    by (simp only: add_assoc add_minus_cancel) simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   414
  then show "- (a + b) = - b + - a"
34147
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   415
    by (rule minus_unique)
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   416
qed
319616f4eecf generalize lemma add_minus_cancel, add lemma minus_add, simplify some proofs
huffman
parents: 34146
diff changeset
   417
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   418
lemma right_minus_eq [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   419
  "a - b = 0 \<longleftrightarrow> a = b"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   420
proof
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   421
  assume "a - b = 0"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   422
  have "a = (a - b) + b" by (simp add: add_assoc)
23085
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   423
  also have "\<dots> = b" using `a - b = 0` by simp
fd30d75a6614 Introduced new classes monoid_add and group_add
nipkow
parents: 22997
diff changeset
   424
  finally show "a = b" .
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   425
next
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   426
  assume "a = b" thus "a - b = 0" by simp
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   427
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   428
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   429
lemma eq_iff_diff_eq_0:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   430
  "a = b \<longleftrightarrow> a - b = 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   431
  by (fact right_minus_eq [symmetric])
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   432
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   433
lemma diff_0 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   434
  "0 - a = - a"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   435
  by (simp only: diff_conv_add_uminus add_0_left)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   436
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   437
lemma diff_0_right [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   438
  "a - 0 = a" 
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   439
  by (simp only: diff_conv_add_uminus minus_zero add_0_right)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   440
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   441
lemma diff_minus_eq_add [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   442
  "a - - b = a + b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   443
  by (simp only: diff_conv_add_uminus minus_minus)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   444
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   445
lemma neg_equal_iff_equal [simp]:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   446
  "- a = - b \<longleftrightarrow> a = b" 
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   447
proof 
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   448
  assume "- a = - b"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   449
  hence "- (- a) = - (- b)" by simp
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   450
  thus "a = b" by simp
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   451
next
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   452
  assume "a = b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   453
  thus "- a = - b" by simp
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   454
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   455
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   456
lemma neg_equal_0_iff_equal [simp]:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   457
  "- a = 0 \<longleftrightarrow> a = 0"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   458
  by (subst neg_equal_iff_equal [symmetric]) simp
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   459
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   460
lemma neg_0_equal_iff_equal [simp]:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   461
  "0 = - a \<longleftrightarrow> 0 = a"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   462
  by (subst neg_equal_iff_equal [symmetric]) simp
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   463
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   464
text{*The next two equations can make the simplifier loop!*}
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   465
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   466
lemma equation_minus_iff:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   467
  "a = - b \<longleftrightarrow> b = - a"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   468
proof -
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   469
  have "- (- a) = - b \<longleftrightarrow> - a = b" by (rule neg_equal_iff_equal)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   470
  thus ?thesis by (simp add: eq_commute)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   471
qed
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   472
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   473
lemma minus_equation_iff:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   474
  "- a = b \<longleftrightarrow> - b = a"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   475
proof -
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   476
  have "- a = - (- b) \<longleftrightarrow> a = -b" by (rule neg_equal_iff_equal)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   477
  thus ?thesis by (simp add: eq_commute)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   478
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   479
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   480
lemma eq_neg_iff_add_eq_0:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   481
  "a = - b \<longleftrightarrow> a + b = 0"
29914
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   482
proof
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   483
  assume "a = - b" then show "a + b = 0" by simp
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   484
next
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   485
  assume "a + b = 0"
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   486
  moreover have "a + (b + - b) = (a + b) + - b"
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   487
    by (simp only: add_assoc)
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   488
  ultimately show "a = - b" by simp
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   489
qed
c9ced4f54e82 generalize lemma eq_neg_iff_add_eq_0, and move to OrderedGroup
huffman
parents: 29904
diff changeset
   490
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   491
lemma add_eq_0_iff2:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   492
  "a + b = 0 \<longleftrightarrow> a = - b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   493
  by (fact eq_neg_iff_add_eq_0 [symmetric])
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   494
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   495
lemma neg_eq_iff_add_eq_0:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   496
  "- a = b \<longleftrightarrow> a + b = 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   497
  by (auto simp add: add_eq_0_iff2)
44348
40101794c52f move lemma add_eq_0_iff to Groups.thy
huffman
parents: 42248
diff changeset
   498
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   499
lemma add_eq_0_iff:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   500
  "a + b = 0 \<longleftrightarrow> b = - a"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   501
  by (auto simp add: neg_eq_iff_add_eq_0 [symmetric])
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   502
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   503
lemma minus_diff_eq [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   504
  "- (a - b) = b - a"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   505
  by (simp only: neg_eq_iff_add_eq_0 diff_conv_add_uminus add_assoc minus_add_cancel) simp
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   506
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   507
lemma add_diff_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   508
  "a + (b - c) = (a + b) - c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   509
  by (simp only: diff_conv_add_uminus add_assoc)
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   510
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   511
lemma diff_add_eq_diff_diff_swap:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   512
  "a - (b + c) = a - c - b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   513
  by (simp only: diff_conv_add_uminus add_assoc minus_add)
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   514
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   515
lemma diff_eq_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   516
  "a - b = c \<longleftrightarrow> a = c + b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   517
  by auto
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   518
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   519
lemma eq_diff_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   520
  "a = c - b \<longleftrightarrow> a + b = c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   521
  by auto
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   522
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   523
lemma diff_diff_eq2 [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   524
  "a - (b - c) = (a + c) - b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   525
  by (simp only: diff_conv_add_uminus add_assoc) simp
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   526
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   527
lemma diff_eq_diff_eq:
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   528
  "a - b = c - d \<Longrightarrow> a = b \<longleftrightarrow> c = d"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   529
  by (simp only: eq_iff_diff_eq_0 [of a b] eq_iff_diff_eq_0 [of c d])
45548
3e2722d66169 Groups.thy: generalize several lemmas from class ab_group_add to class group_add
huffman
parents: 45294
diff changeset
   530
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   531
end
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   532
25762
c03e9d04b3e4 splitted class uminus from class minus
haftmann
parents: 25613
diff changeset
   533
class ab_group_add = minus + uminus + comm_monoid_add +
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   534
  assumes ab_left_minus: "- a + a = 0"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   535
  assumes ab_add_uminus_conv_diff: "a - b = a + (- b)"
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   536
begin
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   537
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
   538
subclass group_add
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   539
  proof qed (simp_all add: ab_left_minus ab_add_uminus_conv_diff)
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   540
29904
856f16a3b436 add class cancel_comm_monoid_add
huffman
parents: 29886
diff changeset
   541
subclass cancel_comm_monoid_add
28823
dcbef866c9e2 tuned unfold_locales invocation
haftmann
parents: 28262
diff changeset
   542
proof
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   543
  fix a b c :: 'a
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   544
  assume "a + b = a + c"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   545
  then have "- a + a + b = - a + a + c"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   546
    by (simp only: add_assoc)
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   547
  then show "b = c" by simp
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   548
qed
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   549
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   550
lemma uminus_add_conv_diff [simp]:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   551
  "- a + b = b - a"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   552
  by (simp add: add_commute)
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   553
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   554
lemma minus_add_distrib [simp]:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   555
  "- (a + b) = - a + - b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   556
  by (simp add: algebra_simps)
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   557
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   558
lemma diff_add_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   559
  "(a - b) + c = (a + c) - b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   560
  by (simp add: algebra_simps)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   561
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   562
lemma diff_diff_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   563
  "(a - b) - c = a - (b + c)"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   564
  by (simp add: algebra_simps)
30629
5cd9b19edef3 move diff_eq_0_iff_eq into class locale context
huffman
parents: 29914
diff changeset
   565
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   566
lemma diff_add_eq_diff_diff:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   567
  "a - (b + c) = a - b - c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   568
  using diff_add_eq_diff_diff_swap [of a c b] by (simp add: add.commute)
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   569
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   570
lemma add_diff_cancel_left [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   571
  "(c + a) - (c + b) = a - b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   572
  by (simp add: algebra_simps)
48556
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
   573
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   574
end
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   575
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
   576
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   577
subsection {* (Partially) Ordered Groups *} 
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   578
35301
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   579
text {*
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   580
  The theory of partially ordered groups is taken from the books:
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   581
  \begin{itemize}
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   582
  \item \emph{Lattice Theory} by Garret Birkhoff, American Mathematical Society 1979 
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   583
  \item \emph{Partially Ordered Algebraic Systems}, Pergamon Press 1963
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   584
  \end{itemize}
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   585
  Most of the used notions can also be looked up in 
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   586
  \begin{itemize}
54703
499f92dc6e45 more antiquotations;
wenzelm
parents: 54250
diff changeset
   587
  \item @{url "http://www.mathworld.com"} by Eric Weisstein et. al.
35301
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   588
  \item \emph{Algebra I} by van der Waerden, Springer.
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   589
  \end{itemize}
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   590
*}
90e42f9ba4d1 distributed theory Algebras to theories Groups and Lattices
haftmann
parents: 35267
diff changeset
   591
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   592
class ordered_ab_semigroup_add = order + ab_semigroup_add +
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   593
  assumes add_left_mono: "a \<le> b \<Longrightarrow> c + a \<le> c + b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   594
begin
24380
c215e256beca moved ordered_ab_semigroup_add to OrderedGroup.thy
haftmann
parents: 24286
diff changeset
   595
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   596
lemma add_right_mono:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   597
  "a \<le> b \<Longrightarrow> a + c \<le> b + c"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   598
by (simp add: add_commute [of _ c] add_left_mono)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   599
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   600
text {* non-strict, in both arguments *}
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   601
lemma add_mono:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   602
  "a \<le> b \<Longrightarrow> c \<le> d \<Longrightarrow> a + c \<le> b + d"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   603
  apply (erule add_right_mono [THEN order_trans])
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   604
  apply (simp add: add_commute add_left_mono)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   605
  done
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   606
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   607
end
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   608
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   609
class ordered_cancel_ab_semigroup_add =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   610
  ordered_ab_semigroup_add + cancel_ab_semigroup_add
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   611
begin
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   612
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   613
lemma add_strict_left_mono:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   614
  "a < b \<Longrightarrow> c + a < c + b"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   615
by (auto simp add: less_le add_left_mono)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   616
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   617
lemma add_strict_right_mono:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   618
  "a < b \<Longrightarrow> a + c < b + c"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   619
by (simp add: add_commute [of _ c] add_strict_left_mono)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   620
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   621
text{*Strict monotonicity in both arguments*}
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   622
lemma add_strict_mono:
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   623
  "a < b \<Longrightarrow> c < d \<Longrightarrow> a + c < b + d"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   624
apply (erule add_strict_right_mono [THEN less_trans])
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   625
apply (erule add_strict_left_mono)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   626
done
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   627
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   628
lemma add_less_le_mono:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   629
  "a < b \<Longrightarrow> c \<le> d \<Longrightarrow> a + c < b + d"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   630
apply (erule add_strict_right_mono [THEN less_le_trans])
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   631
apply (erule add_left_mono)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   632
done
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   633
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   634
lemma add_le_less_mono:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   635
  "a \<le> b \<Longrightarrow> c < d \<Longrightarrow> a + c < b + d"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   636
apply (erule add_right_mono [THEN le_less_trans])
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   637
apply (erule add_strict_left_mono) 
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   638
done
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   639
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   640
end
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   641
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   642
class ordered_ab_semigroup_add_imp_le =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   643
  ordered_cancel_ab_semigroup_add +
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   644
  assumes add_le_imp_le_left: "c + a \<le> c + b \<Longrightarrow> a \<le> b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   645
begin
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   646
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   647
lemma add_less_imp_less_left:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   648
  assumes less: "c + a < c + b" shows "a < b"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   649
proof -
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   650
  from less have le: "c + a <= c + b" by (simp add: order_le_less)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   651
  have "a <= b" 
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   652
    apply (insert le)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   653
    apply (drule add_le_imp_le_left)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   654
    by (insert le, drule add_le_imp_le_left, assumption)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   655
  moreover have "a \<noteq> b"
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   656
  proof (rule ccontr)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   657
    assume "~(a \<noteq> b)"
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   658
    then have "a = b" by simp
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   659
    then have "c + a = c + b" by simp
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   660
    with less show "False"by simp
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   661
  qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   662
  ultimately show "a < b" by (simp add: order_le_less)
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   663
qed
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   664
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   665
lemma add_less_imp_less_right:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   666
  "a + c < b + c \<Longrightarrow> a < b"
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   667
apply (rule add_less_imp_less_left [of c])
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   668
apply (simp add: add_commute)  
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   669
done
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   670
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   671
lemma add_less_cancel_left [simp]:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   672
  "c + a < c + b \<longleftrightarrow> a < b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   673
  by (blast intro: add_less_imp_less_left add_strict_left_mono) 
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   674
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   675
lemma add_less_cancel_right [simp]:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   676
  "a + c < b + c \<longleftrightarrow> a < b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   677
  by (blast intro: add_less_imp_less_right add_strict_right_mono)
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   678
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   679
lemma add_le_cancel_left [simp]:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   680
  "c + a \<le> c + b \<longleftrightarrow> a \<le> b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   681
  by (auto, drule add_le_imp_le_left, simp_all add: add_left_mono) 
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   682
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   683
lemma add_le_cancel_right [simp]:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   684
  "a + c \<le> b + c \<longleftrightarrow> a \<le> b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   685
  by (simp add: add_commute [of a c] add_commute [of b c])
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   686
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
   687
lemma add_le_imp_le_right:
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   688
  "a + c \<le> b + c \<Longrightarrow> a \<le> b"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   689
by simp
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   690
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   691
lemma max_add_distrib_left:
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   692
  "max x y + z = max (x + z) (y + z)"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   693
  unfolding max_def by auto
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   694
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   695
lemma min_add_distrib_left:
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   696
  "min x y + z = min (x + z) (y + z)"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   697
  unfolding min_def by auto
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   698
44848
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   699
lemma max_add_distrib_right:
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   700
  "x + max y z = max (x + y) (x + z)"
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   701
  unfolding max_def by auto
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   702
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   703
lemma min_add_distrib_right:
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   704
  "x + min y z = min (x + y) (x + z)"
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   705
  unfolding min_def by auto
f4d0b060c7ca remove lemmas nat_add_min_{left,right} in favor of generic lemmas min_add_distrib_{left,right}
huffman
parents: 44433
diff changeset
   706
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   707
end
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   708
52289
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   709
class ordered_cancel_comm_monoid_diff = comm_monoid_diff + ordered_ab_semigroup_add_imp_le +
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   710
  assumes le_iff_add: "a \<le> b \<longleftrightarrow> (\<exists>c. b = a + c)"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   711
begin
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   712
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   713
context
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   714
  fixes a b
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   715
  assumes "a \<le> b"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   716
begin
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   717
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   718
lemma add_diff_inverse:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   719
  "a + (b - a) = b"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   720
  using `a \<le> b` by (auto simp add: le_iff_add)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   721
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   722
lemma add_diff_assoc:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   723
  "c + (b - a) = c + b - a"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   724
  using `a \<le> b` by (auto simp add: le_iff_add add_left_commute [of c])
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   725
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   726
lemma add_diff_assoc2:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   727
  "b - a + c = b + c - a"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   728
  using `a \<le> b` by (auto simp add: le_iff_add add_assoc)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   729
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   730
lemma diff_add_assoc:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   731
  "c + b - a = c + (b - a)"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   732
  using `a \<le> b` by (simp add: add_commute add_diff_assoc)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   733
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   734
lemma diff_add_assoc2:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   735
  "b + c - a = b - a + c"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   736
  using `a \<le> b`by (simp add: add_commute add_diff_assoc)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   737
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   738
lemma diff_diff_right:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   739
  "c - (b - a) = c + a - b"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   740
  by (simp add: add_diff_inverse add_diff_cancel_left [of a c "b - a", symmetric] add_commute)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   741
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   742
lemma diff_add:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   743
  "b - a + a = b"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   744
  by (simp add: add_commute add_diff_inverse)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   745
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   746
lemma le_add_diff:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   747
  "c \<le> b + c - a"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   748
  by (auto simp add: add_commute diff_add_assoc2 le_iff_add)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   749
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   750
lemma le_imp_diff_is_add:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   751
  "a \<le> b \<Longrightarrow> b - a = c \<longleftrightarrow> b = c + a"
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   752
  by (auto simp add: add_commute add_diff_inverse)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   753
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   754
lemma le_diff_conv2:
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   755
  "c \<le> b - a \<longleftrightarrow> c + a \<le> b" (is "?P \<longleftrightarrow> ?Q")
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   756
proof
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   757
  assume ?P
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   758
  then have "c + a \<le> b - a + a" by (rule add_right_mono)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   759
  then show ?Q by (simp add: add_diff_inverse add_commute)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   760
next
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   761
  assume ?Q
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   762
  then have "a + c \<le> a + (b - a)" by (simp add: add_diff_inverse add_commute)
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   763
  then show ?P by simp
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   764
qed
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   765
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   766
end
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   767
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   768
end
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   769
83ce5d2841e7 type class for confined subtraction
haftmann
parents: 52210
diff changeset
   770
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   771
subsection {* Support for reasoning about signs *}
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   772
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   773
class ordered_comm_monoid_add =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   774
  ordered_cancel_ab_semigroup_add + comm_monoid_add
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   775
begin
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   776
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   777
lemma add_pos_nonneg:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   778
  assumes "0 < a" and "0 \<le> b" shows "0 < a + b"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   779
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   780
  have "0 + 0 < a + b" 
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   781
    using assms by (rule add_less_le_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   782
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   783
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   784
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   785
lemma add_pos_pos:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   786
  assumes "0 < a" and "0 < b" shows "0 < a + b"
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   787
by (rule add_pos_nonneg) (insert assms, auto)
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   788
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   789
lemma add_nonneg_pos:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   790
  assumes "0 \<le> a" and "0 < b" shows "0 < a + b"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   791
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   792
  have "0 + 0 < a + b" 
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   793
    using assms by (rule add_le_less_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   794
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   795
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   796
36977
71c8973a604b declare add_nonneg_nonneg [simp]; remove now-redundant lemmas realpow_two_le_order(2)
huffman
parents: 36348
diff changeset
   797
lemma add_nonneg_nonneg [simp]:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   798
  assumes "0 \<le> a" and "0 \<le> b" shows "0 \<le> a + b"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   799
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   800
  have "0 + 0 \<le> a + b" 
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   801
    using assms by (rule add_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   802
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   803
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   804
30691
0047f57f6669 lemmas add_sign_intros
huffman
parents: 30629
diff changeset
   805
lemma add_neg_nonpos:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   806
  assumes "a < 0" and "b \<le> 0" shows "a + b < 0"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   807
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   808
  have "a + b < 0 + 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   809
    using assms by (rule add_less_le_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   810
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   811
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   812
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   813
lemma add_neg_neg: 
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   814
  assumes "a < 0" and "b < 0" shows "a + b < 0"
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   815
by (rule add_neg_nonpos) (insert assms, auto)
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   816
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   817
lemma add_nonpos_neg:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   818
  assumes "a \<le> 0" and "b < 0" shows "a + b < 0"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   819
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   820
  have "a + b < 0 + 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   821
    using assms by (rule add_le_less_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   822
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   823
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   824
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   825
lemma add_nonpos_nonpos:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   826
  assumes "a \<le> 0" and "b \<le> 0" shows "a + b \<le> 0"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   827
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   828
  have "a + b \<le> 0 + 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   829
    using assms by (rule add_mono)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   830
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   831
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   832
30691
0047f57f6669 lemmas add_sign_intros
huffman
parents: 30629
diff changeset
   833
lemmas add_sign_intros =
0047f57f6669 lemmas add_sign_intros
huffman
parents: 30629
diff changeset
   834
  add_pos_nonneg add_pos_pos add_nonneg_pos add_nonneg_nonneg
0047f57f6669 lemmas add_sign_intros
huffman
parents: 30629
diff changeset
   835
  add_neg_nonpos add_neg_neg add_nonpos_neg add_nonpos_nonpos
0047f57f6669 lemmas add_sign_intros
huffman
parents: 30629
diff changeset
   836
29886
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   837
lemma add_nonneg_eq_0_iff:
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   838
  assumes x: "0 \<le> x" and y: "0 \<le> y"
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   839
  shows "x + y = 0 \<longleftrightarrow> x = 0 \<and> y = 0"
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   840
proof (intro iffI conjI)
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   841
  have "x = x + 0" by simp
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   842
  also have "x + 0 \<le> x + y" using y by (rule add_left_mono)
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   843
  also assume "x + y = 0"
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   844
  also have "0 \<le> x" using x .
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   845
  finally show "x = 0" .
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   846
next
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   847
  have "y = 0 + y" by simp
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   848
  also have "0 + y \<le> x + y" using x by (rule add_right_mono)
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   849
  also assume "x + y = 0"
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   850
  also have "0 \<le> y" using y .
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   851
  finally show "y = 0" .
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   852
next
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   853
  assume "x = 0 \<and> y = 0"
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   854
  then show "x + y = 0" by simp
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   855
qed
b8a6b9c56fdd add lemma add_nonneg_eq_0_iff
huffman
parents: 29833
diff changeset
   856
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   857
lemma add_increasing:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   858
  "0 \<le> a \<Longrightarrow> b \<le> c \<Longrightarrow> b \<le> a + c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   859
  by (insert add_mono [of 0 a b c], simp)
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   860
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   861
lemma add_increasing2:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   862
  "0 \<le> c \<Longrightarrow> b \<le> a \<Longrightarrow> b \<le> a + c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   863
  by (simp add: add_increasing add_commute [of a])
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   864
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   865
lemma add_strict_increasing:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   866
  "0 < a \<Longrightarrow> b \<le> c \<Longrightarrow> b < a + c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   867
  by (insert add_less_le_mono [of 0 a b c], simp)
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   868
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   869
lemma add_strict_increasing2:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   870
  "0 \<le> a \<Longrightarrow> b < c \<Longrightarrow> b < a + c"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   871
  by (insert add_le_less_mono [of 0 a b c], simp)
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   872
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   873
end
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   874
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   875
class ordered_ab_group_add =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   876
  ab_group_add + ordered_ab_semigroup_add
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   877
begin
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   878
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   879
subclass ordered_cancel_ab_semigroup_add ..
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   880
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   881
subclass ordered_ab_semigroup_add_imp_le
28823
dcbef866c9e2 tuned unfold_locales invocation
haftmann
parents: 28262
diff changeset
   882
proof
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   883
  fix a b c :: 'a
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   884
  assume "c + a \<le> c + b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   885
  hence "(-c) + (c + a) \<le> (-c) + (c + b)" by (rule add_left_mono)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   886
  hence "((-c) + c) + a \<le> ((-c) + c) + b" by (simp only: add_assoc)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   887
  thus "a \<le> b" by simp
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   888
qed
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
   889
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
   890
subclass ordered_comm_monoid_add ..
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
   891
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   892
lemma add_less_same_cancel1 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   893
  "b + a < b \<longleftrightarrow> a < 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   894
  using add_less_cancel_left [of _ _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   895
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   896
lemma add_less_same_cancel2 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   897
  "a + b < b \<longleftrightarrow> a < 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   898
  using add_less_cancel_right [of _ _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   899
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   900
lemma less_add_same_cancel1 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   901
  "a < a + b \<longleftrightarrow> 0 < b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   902
  using add_less_cancel_left [of _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   903
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   904
lemma less_add_same_cancel2 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   905
  "a < b + a \<longleftrightarrow> 0 < b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   906
  using add_less_cancel_right [of 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   907
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   908
lemma add_le_same_cancel1 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   909
  "b + a \<le> b \<longleftrightarrow> a \<le> 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   910
  using add_le_cancel_left [of _ _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   911
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   912
lemma add_le_same_cancel2 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   913
  "a + b \<le> b \<longleftrightarrow> a \<le> 0"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   914
  using add_le_cancel_right [of _ _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   915
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   916
lemma le_add_same_cancel1 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   917
  "a \<le> a + b \<longleftrightarrow> 0 \<le> b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   918
  using add_le_cancel_left [of _ 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   919
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   920
lemma le_add_same_cancel2 [simp]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   921
  "a \<le> b + a \<longleftrightarrow> 0 \<le> b"
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   922
  using add_le_cancel_right [of 0] by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   923
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   924
lemma max_diff_distrib_left:
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   925
  shows "max x y - z = max (x - z) (y - z)"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   926
  using max_add_distrib_left [of x y "- z"] by simp
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   927
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   928
lemma min_diff_distrib_left:
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   929
  shows "min x y - z = min (x - z) (y - z)"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   930
  using min_add_distrib_left [of x y "- z"] by simp
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   931
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   932
lemma le_imp_neg_le:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   933
  assumes "a \<le> b" shows "-b \<le> -a"
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   934
proof -
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   935
  have "-a+a \<le> -a+b" using `a \<le> b` by (rule add_left_mono) 
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   936
  then have "0 \<le> -a+b" by simp
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   937
  then have "0 + (-b) \<le> (-a + b) + (-b)" by (rule add_right_mono) 
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   938
  then show ?thesis by (simp add: algebra_simps)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   939
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   940
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   941
lemma neg_le_iff_le [simp]: "- b \<le> - a \<longleftrightarrow> a \<le> b"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   942
proof 
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   943
  assume "- b \<le> - a"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   944
  hence "- (- a) \<le> - (- b)" by (rule le_imp_neg_le)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   945
  thus "a\<le>b" by simp
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   946
next
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   947
  assume "a\<le>b"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   948
  thus "-b \<le> -a" by (rule le_imp_neg_le)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   949
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   950
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   951
lemma neg_le_0_iff_le [simp]: "- a \<le> 0 \<longleftrightarrow> 0 \<le> a"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   952
by (subst neg_le_iff_le [symmetric], simp)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   953
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   954
lemma neg_0_le_iff_le [simp]: "0 \<le> - a \<longleftrightarrow> a \<le> 0"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   955
by (subst neg_le_iff_le [symmetric], simp)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   956
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   957
lemma neg_less_iff_less [simp]: "- b < - a \<longleftrightarrow> a < b"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   958
by (force simp add: less_le) 
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   959
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   960
lemma neg_less_0_iff_less [simp]: "- a < 0 \<longleftrightarrow> 0 < a"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   961
by (subst neg_less_iff_less [symmetric], simp)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   962
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   963
lemma neg_0_less_iff_less [simp]: "0 < - a \<longleftrightarrow> a < 0"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   964
by (subst neg_less_iff_less [symmetric], simp)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   965
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   966
text{*The next several equations can make the simplifier loop!*}
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   967
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   968
lemma less_minus_iff: "a < - b \<longleftrightarrow> b < - a"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   969
proof -
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   970
  have "(- (-a) < - b) = (b < - a)" by (rule neg_less_iff_less)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   971
  thus ?thesis by simp
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   972
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   973
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   974
lemma minus_less_iff: "- a < b \<longleftrightarrow> - b < a"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   975
proof -
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   976
  have "(- a < - (-b)) = (- b < a)" by (rule neg_less_iff_less)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   977
  thus ?thesis by simp
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   978
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   979
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   980
lemma le_minus_iff: "a \<le> - b \<longleftrightarrow> b \<le> - a"
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   981
proof -
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   982
  have mm: "!! a (b::'a). (-(-a)) < -b \<Longrightarrow> -(-b) < -a" by (simp only: minus_less_iff)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   983
  have "(- (- a) <= -b) = (b <= - a)" 
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   984
    apply (auto simp only: le_less)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   985
    apply (drule mm)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   986
    apply (simp_all)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   987
    apply (drule mm[simplified], assumption)
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   988
    done
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   989
  then show ?thesis by simp
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   990
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   991
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   992
lemma minus_le_iff: "- a \<le> b \<longleftrightarrow> - b \<le> a"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
   993
by (auto simp add: le_less minus_less_iff)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   994
54148
c8cc5ab4a863 killed more "no_atp"s
blanchet
parents: 54147
diff changeset
   995
lemma diff_less_0_iff_less [simp]:
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
   996
  "a - b < 0 \<longleftrightarrow> a < b"
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
   997
proof -
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
   998
  have "a - b < 0 \<longleftrightarrow> a + (- b) < b + (- b)" by simp
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
   999
  also have "... \<longleftrightarrow> a < b" by (simp only: add_less_cancel_right)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1000
  finally show ?thesis .
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1001
qed
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1002
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1003
lemmas less_iff_diff_less_0 = diff_less_0_iff_less [symmetric]
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1004
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1005
lemma diff_less_eq [algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1006
  "a - b < c \<longleftrightarrow> a < c + b"
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1007
apply (subst less_iff_diff_less_0 [of a])
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1008
apply (rule less_iff_diff_less_0 [of _ c, THEN ssubst])
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1009
apply (simp add: algebra_simps)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1010
done
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1011
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1012
lemma less_diff_eq[algebra_simps, field_simps]:
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1013
  "a < c - b \<longleftrightarrow> a + b < c"
36302
4e7f5b22dd7d more localization; tuned proofs
haftmann
parents: 36176
diff changeset
  1014
apply (subst less_iff_diff_less_0 [of "a + b"])
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1015
apply (subst less_iff_diff_less_0 [of a])
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1016
apply (simp add: algebra_simps)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1017
done
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1018
36348
89c54f51f55a dropped group_simps, ring_simps, field_eq_simps; classes division_ring_inverse_zero, field_inverse_zero, linordered_field_inverse_zero
haftmann
parents: 36343
diff changeset
  1019
lemma diff_le_eq[algebra_simps, field_simps]: "a - b \<le> c \<longleftrightarrow> a \<le> c + b"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1020
by (auto simp add: le_less diff_less_eq )
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1021
36348
89c54f51f55a dropped group_simps, ring_simps, field_eq_simps; classes division_ring_inverse_zero, field_inverse_zero, linordered_field_inverse_zero
haftmann
parents: 36343
diff changeset
  1022
lemma le_diff_eq[algebra_simps, field_simps]: "a \<le> c - b \<longleftrightarrow> a + b \<le> c"
54230
b1d955791529 more simplification rules on unary and binary minus
haftmann
parents: 54148
diff changeset
  1023
by (auto simp add: le_less less_diff_eq)
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1024
54148
c8cc5ab4a863 killed more "no_atp"s
blanchet
parents: 54147
diff changeset
  1025
lemma diff_le_0_iff_le [simp]:
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1026
  "a - b \<le> 0 \<longleftrightarrow> a \<le> b"
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1027
  by (simp add: algebra_simps)
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1028
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1029
lemmas le_iff_diff_le_0 = diff_le_0_iff_le [symmetric]
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1030
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1031
lemma diff_eq_diff_less:
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1032
  "a - b = c - d \<Longrightarrow> a < b \<longleftrightarrow> c < d"
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1033
  by (auto simp only: less_iff_diff_less_0 [of a b] less_iff_diff_less_0 [of c d])
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1034
37889
0d8058e0c270 keep explicit diff_def as legacy theorem; modernized abel_cancel simproc setup
haftmann
parents: 37884
diff changeset
  1035
lemma diff_eq_diff_less_eq:
0d8058e0c270 keep explicit diff_def as legacy theorem; modernized abel_cancel simproc setup
haftmann
parents: 37884
diff changeset
  1036
  "a - b = c - d \<Longrightarrow> a \<le> b \<longleftrightarrow> c \<le> d"
0d8058e0c270 keep explicit diff_def as legacy theorem; modernized abel_cancel simproc setup
haftmann
parents: 37884
diff changeset
  1037
  by (auto simp only: le_iff_diff_le_0 [of a b] le_iff_diff_le_0 [of c d])
25077
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1038
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1039
end
c2ec5e589d78 continued localization
haftmann
parents: 25062
diff changeset
  1040
48891
c0eafbd55de3 prefer ML_file over old uses;
wenzelm
parents: 48556
diff changeset
  1041
ML_file "Tools/group_cancel.ML"
48556
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1042
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1043
simproc_setup group_cancel_add ("a + b::'a::ab_group_add") =
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1044
  {* fn phi => fn ss => try Group_Cancel.cancel_add_conv *}
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1045
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1046
simproc_setup group_cancel_diff ("a - b::'a::ab_group_add") =
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1047
  {* fn phi => fn ss => try Group_Cancel.cancel_diff_conv *}
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1048
48556
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1049
simproc_setup group_cancel_eq ("a = (b::'a::ab_group_add)") =
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1050
  {* fn phi => fn ss => try Group_Cancel.cancel_eq_conv *}
37889
0d8058e0c270 keep explicit diff_def as legacy theorem; modernized abel_cancel simproc setup
haftmann
parents: 37884
diff changeset
  1051
48556
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1052
simproc_setup group_cancel_le ("a \<le> (b::'a::ordered_ab_group_add)") =
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1053
  {* fn phi => fn ss => try Group_Cancel.cancel_le_conv *}
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1054
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1055
simproc_setup group_cancel_less ("a < (b::'a::ordered_ab_group_add)") =
62a3fbf9d35b replace abel_cancel simprocs with functionally equivalent, but simpler and faster ones
huffman
parents: 45548
diff changeset
  1056
  {* fn phi => fn ss => try Group_Cancel.cancel_less_conv *}
37884
314a88278715 discontinued pretending that abel_cancel is logic-independent; cleaned up junk
haftmann
parents: 36977
diff changeset
  1057
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1058
class linordered_ab_semigroup_add =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1059
  linorder + ordered_ab_semigroup_add
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1060
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1061
class linordered_cancel_ab_semigroup_add =
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1062
  linorder + ordered_cancel_ab_semigroup_add
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1063
begin
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1064
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1065
subclass linordered_ab_semigroup_add ..
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1066
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1067
subclass ordered_ab_semigroup_add_imp_le
28823
dcbef866c9e2 tuned unfold_locales invocation
haftmann
parents: 28262
diff changeset
  1068
proof
25062
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1069
  fix a b c :: 'a
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1070
  assume le: "c + a <= c + b"  
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1071
  show "a <= b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1072
  proof (rule ccontr)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1073
    assume w: "~ a \<le> b"
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1074
    hence "b <= a" by (simp add: linorder_not_le)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1075
    hence le2: "c + b <= c + a" by (rule add_left_mono)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1076
    have "a = b" 
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1077
      apply (insert le)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1078
      apply (insert le2)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1079
      apply (drule antisym, simp_all)
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1080
      done
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1081
    with w show False 
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1082
      by (simp add: linorder_not_le [symmetric])
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1083
  qed
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1084
qed
af5ef0d4d655 global class syntax
haftmann
parents: 24748
diff changeset
  1085
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1086
end
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1087
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1088
class linordered_ab_group_add = linorder + ordered_ab_group_add
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1089
begin
25230
022029099a83 continued localization
haftmann
parents: 25194
diff changeset
  1090
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1091
subclass linordered_cancel_ab_semigroup_add ..
25230
022029099a83 continued localization
haftmann
parents: 25194
diff changeset
  1092
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1093
lemma equal_neg_zero [simp]:
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1094
  "a = - a \<longleftrightarrow> a = 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1095
proof
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1096
  assume "a = 0" then show "a = - a" by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1097
next
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1098
  assume A: "a = - a" show "a = 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1099
  proof (cases "0 \<le> a")
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1100
    case True with A have "0 \<le> - a" by auto
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1101
    with le_minus_iff have "a \<le> 0" by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1102
    with True show ?thesis by (auto intro: order_trans)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1103
  next
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1104
    case False then have B: "a \<le> 0" by auto
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1105
    with A have "- a \<le> 0" by auto
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1106
    with B show ?thesis by (auto intro: order_trans)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1107
  qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1108
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1109
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1110
lemma neg_equal_zero [simp]:
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1111
  "- a = a \<longleftrightarrow> a = 0"
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1112
  by (auto dest: sym)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1113
54250
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1114
lemma neg_less_eq_nonneg [simp]:
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1115
  "- a \<le> a \<longleftrightarrow> 0 \<le> a"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1116
proof
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1117
  assume A: "- a \<le> a" show "0 \<le> a"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1118
  proof (rule classical)
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1119
    assume "\<not> 0 \<le> a"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1120
    then have "a < 0" by auto
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1121
    with A have "- a < 0" by (rule le_less_trans)
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1122
    then show ?thesis by auto
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1123
  qed
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1124
next
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1125
  assume A: "0 \<le> a" show "- a \<le> a"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1126
  proof (rule order_trans)
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1127
    show "- a \<le> 0" using A by (simp add: minus_le_iff)
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1128
  next
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1129
    show "0 \<le> a" using A .
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1130
  qed
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1131
qed
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1132
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1133
lemma neg_less_pos [simp]:
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1134
  "- a < a \<longleftrightarrow> 0 < a"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1135
  by (auto simp add: less_le)
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1136
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1137
lemma less_eq_neg_nonpos [simp]:
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1138
  "a \<le> - a \<longleftrightarrow> a \<le> 0"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1139
  using neg_less_eq_nonneg [of "- a"] by simp
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1140
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1141
lemma less_neg_neg [simp]:
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1142
  "a < - a \<longleftrightarrow> a < 0"
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1143
  using neg_less_pos [of "- a"] by simp
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1144
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1145
lemma double_zero [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1146
  "a + a = 0 \<longleftrightarrow> a = 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1147
proof
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1148
  assume assm: "a + a = 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1149
  then have a: "- a = a" by (rule minus_unique)
35216
7641e8d831d2 get rid of many duplicate simp rule warnings
huffman
parents: 35092
diff changeset
  1150
  then show "a = 0" by (simp only: neg_equal_zero)
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1151
qed simp
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1152
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1153
lemma double_zero_sym [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1154
  "0 = a + a \<longleftrightarrow> a = 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1155
  by (rule, drule sym) simp_all
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1156
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1157
lemma zero_less_double_add_iff_zero_less_single_add [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1158
  "0 < a + a \<longleftrightarrow> 0 < a"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1159
proof
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1160
  assume "0 < a + a"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1161
  then have "0 - a < a" by (simp only: diff_less_eq)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1162
  then have "- a < a" by simp
54250
7d2544dd3988 fact generalization and name consolidation
haftmann
parents: 54230
diff changeset
  1163
  then show "0 < a" by simp
35036
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1164
next
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1165
  assume "0 < a"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1166
  with this have "0 + 0 < a + a"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1167
    by (rule add_strict_mono)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1168
  then show "0 < a + a" by simp
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1169
qed
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1170
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1171
lemma zero_le_double_add_iff_zero_le_single_add [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1172
  "0 \<le> a + a \<longleftrightarrow> 0 \<le> a"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1173
  by (auto simp add: le_less)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1174
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1175
lemma double_add_less_zero_iff_single_add_less_zero [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1176
  "a + a < 0 \<longleftrightarrow> a < 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1177
proof -
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1178
  have "\<not> a + a < 0 \<longleftrightarrow> \<not> a < 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1179
    by (simp add: not_less)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1180
  then show ?thesis by simp
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1181
qed
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1182
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1183
lemma double_add_le_zero_iff_single_add_le_zero [simp]:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1184
  "a + a \<le> 0 \<longleftrightarrow> a \<le> 0" 
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1185
proof -
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1186
  have "\<not> a + a \<le> 0 \<longleftrightarrow> \<not> a \<le> 0"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1187
    by (simp add: not_le)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1188
  then show ?thesis by simp
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1189
qed
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1190
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1191
lemma minus_max_eq_min:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1192
  "- max x y = min (-x) (-y)"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1193
  by (auto simp add: max_def min_def)
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1194
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1195
lemma minus_min_eq_max:
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1196
  "- min x y = max (-x) (-y)"
b8c8d01cc20d separate library theory for type classes combining lattices with various algebraic structures; more simp rules
haftmann
parents: 35028
diff changeset
  1197
  by (auto simp add: max_def min_def)
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1198
25267
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1199
end
1f745c599b5c proper reinitialisation after subclass
haftmann
parents: 25230
diff changeset
  1200
35092
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1201
class abs =
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1202
  fixes abs :: "'a \<Rightarrow> 'a"
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1203
begin
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1204
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1205
notation (xsymbols)
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1206
  abs  ("\<bar>_\<bar>")
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1207
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1208
notation (HTML output)
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1209
  abs  ("\<bar>_\<bar>")
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1210
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1211
end
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1212
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1213
class sgn =
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1214
  fixes sgn :: "'a \<Rightarrow> 'a"
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1215
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1216
class abs_if = minus + uminus + ord + zero + abs +
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1217
  assumes abs_if: "\<bar>a\<bar> = (if a < 0 then - a else a)"
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1218
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1219
class sgn_if = minus + uminus + zero + one + ord + sgn +
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1220
  assumes sgn_if: "sgn x = (if x = 0 then 0 else if 0 < x then 1 else - 1)"
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1221
begin
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1222
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1223
lemma sgn0 [simp]: "sgn 0 = 0"
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1224
  by (simp add:sgn_if)
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1225
cfe605c54e50 moved less_eq, less to Orderings.thy; moved abs, sgn to Groups.thy
haftmann
parents: 35050
diff changeset
  1226
end
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents:
diff changeset
  1227
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34973
diff changeset
  1228
class ordered_ab_group_add_abs = ordered_ab_group_add + abs +
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1229
  assumes abs_ge_zero [simp]: "\<bar>a\<bar> \<ge> 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1230
    and abs_ge_self: "a \<le> \<bar>a\<bar>"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1231
    and abs_leI: "a \<le> b \<Longrightarrow> - a \<le> b \<Longrightarrow> \<bar>a\<bar> \<le> b"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1232
    and abs_minus_cancel [simp]: "\<bar>-a\<bar> = \<bar>a\<bar>"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1233
    and abs_triangle_ineq: "\<bar>a + b\<bar> \<le> \<bar>a\<bar> + \<bar>b\<bar>"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1234
begin
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1235
25307
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1236
lemma abs_minus_le_zero: "- \<bar>a\<bar> \<le> 0"
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1237
  unfolding neg_le_0_iff_le by simp
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1238
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1239
lemma abs_of_nonneg [simp]:
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
  1240
  assumes nonneg: "0 \<le> a" shows "\<bar>a\<bar> = a"
25307
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1241
proof (rule antisym)
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1242
  from nonneg le_imp_neg_le have "- a \<le> 0" by simp
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1243
  from this nonneg have "- a \<le> a" by (rule order_trans)
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1244
  then show "\<bar>a\<bar> \<le> a" by (auto intro: abs_leI)
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1245
qed (rule abs_ge_self)
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1246
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1247
lemma abs_idempotent [simp]: "\<bar>\<bar>a\<bar>\<bar> = \<bar>a\<bar>"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
  1248
by (rule antisym)
36302
4e7f5b22dd7d more localization; tuned proofs
haftmann
parents: 36176
diff changeset
  1249
   (auto intro!: abs_ge_self abs_leI order_trans [of "- \<bar>a\<bar>" 0 "\<bar>a\<bar>"])
25307
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1250
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1251
lemma abs_eq_0 [simp]: "\<bar>a\<bar> = 0 \<longleftrightarrow> a = 0"
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1252
proof -
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1253
  have "\<bar>a\<bar> = 0 \<Longrightarrow> a = 0"
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1254
  proof (rule antisym)
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1255
    assume zero: "\<bar>a\<bar> = 0"
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1256
    with abs_ge_self show "a \<le> 0" by auto
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1257
    from zero have "\<bar>-a\<bar> = 0" by simp
36302
4e7f5b22dd7d more localization; tuned proofs
haftmann
parents: 36176
diff changeset
  1258
    with abs_ge_self [of "- a"] have "- a \<le> 0" by auto
25307
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1259
    with neg_le_0_iff_le show "0 \<le> a" by auto
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1260
  qed
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1261
  then show ?thesis by auto
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1262
qed
389902f0a0c8 simplified specification of *_abs class
haftmann
parents: 25303
diff changeset
  1263
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1264
lemma abs_zero [simp]: "\<bar>0\<bar> = 0"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
  1265
by simp
16775
c1b87ef4a1c3 added lemmas to OrderedGroup.thy (reasoning about signs, absolute value, triangle inequalities)
avigad
parents: 16417
diff changeset
  1266
54148
c8cc5ab4a863 killed more "no_atp"s
blanchet
parents: 54147
diff changeset
  1267
lemma abs_0_eq [simp]: "0 = \<bar>a\<bar> \<longleftrightarrow> a = 0"
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1268
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1269
  have "0 = \<bar>a\<bar> \<longleftrightarrow> \<bar>a\<bar> = 0" by (simp only: eq_ac)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1270
  thus ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1271
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1272
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1273
lemma abs_le_zero_iff [simp]: "\<bar>a\<bar> \<le> 0 \<longleftrightarrow> a = 0" 
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1274
proof
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1275
  assume "\<bar>a\<bar> \<le> 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1276
  then have "\<bar>a\<bar> = 0" by (rule antisym) simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1277
  thus "a = 0" by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1278
next
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1279
  assume "a = 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1280
  thus "\<bar>a\<bar> \<le> 0" by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1281
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1282
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1283
lemma zero_less_abs_iff [simp]: "0 < \<bar>a\<bar> \<longleftrightarrow> a \<noteq> 0"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
  1284
by (simp add: less_le)
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1285
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1286
lemma abs_not_less_zero [simp]: "\<not> \<bar>a\<bar> < 0"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1287
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1288
  have a: "\<And>x y. x \<le> y \<Longrightarrow> \<not> y < x" by auto
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1289
  show ?thesis by (simp add: a)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1290
qed
16775
c1b87ef4a1c3 added lemmas to OrderedGroup.thy (reasoning about signs, absolute value, triangle inequalities)
avigad
parents: 16417
diff changeset
  1291
25303
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1292
lemma abs_ge_minus_self: "- a \<le> \<bar>a\<bar>"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1293
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1294
  have "- a \<le> \<bar>-a\<bar>" by (rule abs_ge_self)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1295
  then show ?thesis by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1296
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1297
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1298
lemma abs_minus_commute: 
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1299
  "\<bar>a - b\<bar> = \<bar>b - a\<bar>"
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1300
proof -
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1301
  have "\<bar>a - b\<bar> = \<bar>- (a - b)\<bar>" by (simp only: abs_minus_cancel)
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1302
  also have "... = \<bar>b - a\<bar>" by simp
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1303
  finally show ?thesis .
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1304
qed
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1305
0699e20feabd renamed lordered_*_* to lordered_*_add_*; further localization
haftmann
parents: 25267
diff changeset
  1306
lemma abs_of_pos: "0 < a \<Longrightarrow> \<bar>a\<bar> = a"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 29269
diff changeset
  1307
by (rule abs_of_nonneg, rule less_imp_le)
16775
c1b87ef4a1c3 added lemmas to OrderedGroup.thy (reasoning about signs, absolute value, triangle