(* Title: HOL/HOL.thy
Author: Tobias Nipkow, Markus Wenzel, and Larry Paulson
*)
section \<open>The basis of Higher-Order Logic\<close>
theory HOL
imports Pure "~~/src/Tools/Code_Generator"
keywords
"try" "solve_direct" "quickcheck" "print_coercions" "print_claset"
"print_induct_rules" :: diag and
"quickcheck_params" :: thy_decl
begin
ML_file "~~/src/Tools/misc_legacy.ML"
ML_file "~~/src/Tools/try.ML"
ML_file "~~/src/Tools/quickcheck.ML"
ML_file "~~/src/Tools/solve_direct.ML"
ML_file "~~/src/Tools/IsaPlanner/zipper.ML"
ML_file "~~/src/Tools/IsaPlanner/isand.ML"
ML_file "~~/src/Tools/IsaPlanner/rw_inst.ML"
ML_file "~~/src/Provers/hypsubst.ML"
ML_file "~~/src/Provers/splitter.ML"
ML_file "~~/src/Provers/classical.ML"
ML_file "~~/src/Provers/blast.ML"
ML_file "~~/src/Provers/clasimp.ML"
ML_file "~~/src/Tools/eqsubst.ML"
ML_file "~~/src/Provers/quantifier1.ML"
ML_file "~~/src/Tools/atomize_elim.ML"
ML_file "~~/src/Tools/cong_tac.ML"
ML_file "~~/src/Tools/intuitionistic.ML" setup \<open>Intuitionistic.method_setup @{binding iprover}\<close>
ML_file "~~/src/Tools/project_rule.ML"
ML_file "~~/src/Tools/subtyping.ML"
ML_file "~~/src/Tools/case_product.ML"
ML \<open>Plugin_Name.declare_setup @{binding extraction}\<close>
ML \<open>
Plugin_Name.declare_setup @{binding quickcheck_random};
Plugin_Name.declare_setup @{binding quickcheck_exhaustive};
Plugin_Name.declare_setup @{binding quickcheck_bounded_forall};
Plugin_Name.declare_setup @{binding quickcheck_full_exhaustive};
Plugin_Name.declare_setup @{binding quickcheck_narrowing};
\<close>
ML \<open>
Plugin_Name.define_setup @{binding quickcheck}
[@{plugin quickcheck_exhaustive},
@{plugin quickcheck_random},
@{plugin quickcheck_bounded_forall},
@{plugin quickcheck_full_exhaustive},
@{plugin quickcheck_narrowing}]
\<close>
subsection \<open>Primitive logic\<close>
subsubsection \<open>Core syntax\<close>
setup \<open>Axclass.class_axiomatization (@{binding type}, [])\<close>
default_sort type
setup \<open>Object_Logic.add_base_sort @{sort type}\<close>
axiomatization where fun_arity: "OFCLASS('a \<Rightarrow> 'b, type_class)"
instance "fun" :: (type, type) type by (rule fun_arity)
axiomatization where itself_arity: "OFCLASS('a itself, type_class)"
instance itself :: (type) type by (rule itself_arity)
typedecl bool
judgment Trueprop :: "bool \<Rightarrow> prop" ("(_)" 5)
axiomatization implies :: "[bool, bool] \<Rightarrow> bool" (infixr "\<longrightarrow>" 25)
and eq :: "['a, 'a] \<Rightarrow> bool" (infixl "=" 50)
and The :: "('a \<Rightarrow> bool) \<Rightarrow> 'a"
subsubsection \<open>Defined connectives and quantifiers\<close>
definition True :: bool
where "True \<equiv> ((\<lambda>x::bool. x) = (\<lambda>x. x))"
definition All :: "('a \<Rightarrow> bool) \<Rightarrow> bool" (binder "\<forall>" 10)
where "All P \<equiv> (P = (\<lambda>x. True))"
definition Ex :: "('a \<Rightarrow> bool) \<Rightarrow> bool" (binder "\<exists>" 10)
where "Ex P \<equiv> \<forall>Q. (\<forall>x. P x \<longrightarrow> Q) \<longrightarrow> Q"
definition False :: bool
where "False \<equiv> (\<forall>P. P)"
definition Not :: "bool \<Rightarrow> bool" ("\<not> _" [40] 40)
where not_def: "\<not> P \<equiv> P \<longrightarrow> False"
definition conj :: "[bool, bool] \<Rightarrow> bool" (infixr "\<and>" 35)
where and_def: "P \<and> Q \<equiv> \<forall>R. (P \<longrightarrow> Q \<longrightarrow> R) \<longrightarrow> R"
definition disj :: "[bool, bool] \<Rightarrow> bool" (infixr "\<or>" 30)
where or_def: "P \<or> Q \<equiv> \<forall>R. (P \<longrightarrow> R) \<longrightarrow> (Q \<longrightarrow> R) \<longrightarrow> R"
definition Ex1 :: "('a \<Rightarrow> bool) \<Rightarrow> bool"
where "Ex1 P \<equiv> \<exists>x. P x \<and> (\<forall>y. P y \<longrightarrow> y = x)"
subsubsection \<open>Additional concrete syntax\<close>
syntax (ASCII)
"_Ex1" :: "pttrn \<Rightarrow> bool \<Rightarrow> bool" ("(3EX! _./ _)" [0, 10] 10)
syntax (input)
"_Ex1" :: "pttrn \<Rightarrow> bool \<Rightarrow> bool" ("(3?! _./ _)" [0, 10] 10)
syntax "_Ex1" :: "pttrn \<Rightarrow> bool \<Rightarrow> bool" ("(3\<exists>!_./ _)" [0, 10] 10)
translations "\<exists>!x. P" \<rightleftharpoons> "CONST Ex1 (\<lambda>x. P)"
print_translation \<open>
[Syntax_Trans.preserve_binder_abs_tr' @{const_syntax Ex1} @{syntax_const "_Ex1"}]
\<close> \<comment> \<open>to avoid eta-contraction of body\<close>
syntax
"_Not_Ex" :: "idts \<Rightarrow> bool \<Rightarrow> bool" ("(3\<nexists>_./ _)" [0, 10] 10)
"_Not_Ex1" :: "pttrn \<Rightarrow> bool \<Rightarrow> bool" ("(3\<nexists>!_./ _)" [0, 10] 10)
translations
"\<nexists>x. P" \<rightleftharpoons> "\<not> (\<exists>x. P)"
"\<nexists>!x. P" \<rightleftharpoons> "\<not> (\<exists>!x. P)"
abbreviation not_equal :: "['a, 'a] \<Rightarrow> bool" (infixl "\<noteq>" 50)
where "x \<noteq> y \<equiv> \<not> (x = y)"
notation (output)
eq (infix "=" 50) and
not_equal (infix "\<noteq>" 50)
notation (ASCII output)
not_equal (infix "~=" 50)
notation (ASCII)
Not ("~ _" [40] 40) and
conj (infixr "&" 35) and
disj (infixr "|" 30) and
implies (infixr "-->" 25) and
not_equal (infixl "~=" 50)
abbreviation (iff)
iff :: "[bool, bool] \<Rightarrow> bool" (infixr "\<longleftrightarrow>" 25)
where "A \<longleftrightarrow> B \<equiv> A = B"
syntax "_The" :: "[pttrn, bool] \<Rightarrow> 'a" ("(3THE _./ _)" [0, 10] 10)
translations "THE x. P" \<rightleftharpoons> "CONST The (\<lambda>x. P)"
print_translation \<open>
[(@{const_syntax The}, fn _ => fn [Abs abs] =>
let val (x, t) = Syntax_Trans.atomic_abs_tr' abs
in Syntax.const @{syntax_const "_The"} $ x $ t end)]
\<close> \<comment> \<open>To avoid eta-contraction of body\<close>
nonterminal letbinds and letbind
syntax
"_bind" :: "[pttrn, 'a] \<Rightarrow> letbind" ("(2_ =/ _)" 10)
"" :: "letbind \<Rightarrow> letbinds" ("_")
"_binds" :: "[letbind, letbinds] \<Rightarrow> letbinds" ("_;/ _")
"_Let" :: "[letbinds, 'a] \<Rightarrow> 'a" ("(let (_)/ in (_))" [0, 10] 10)
nonterminal case_syn and cases_syn
syntax
"_case_syntax" :: "['a, cases_syn] \<Rightarrow> 'b" ("(case _ of/ _)" 10)
"_case1" :: "['a, 'b] \<Rightarrow> case_syn" ("(2_ \<Rightarrow>/ _)" 10)
"" :: "case_syn \<Rightarrow> cases_syn" ("_")
"_case2" :: "[case_syn, cases_syn] \<Rightarrow> cases_syn" ("_/ | _")
syntax (ASCII)
"_case1" :: "['a, 'b] \<Rightarrow> case_syn" ("(2_ =>/ _)" 10)
notation (ASCII)
All (binder "ALL " 10) and
Ex (binder "EX " 10)
notation (input)
All (binder "! " 10) and
Ex (binder "? " 10)
subsubsection \<open>Axioms and basic definitions\<close>
axiomatization where
refl: "t = (t::'a)" and
subst: "s = t \<Longrightarrow> P s \<Longrightarrow> P t" and
ext: "(\<And>x::'a. (f x ::'b) = g x) \<Longrightarrow> (\<lambda>x. f x) = (\<lambda>x. g x)"
\<comment> \<open>Extensionality is built into the meta-logic, and this rule expresses
a related property. It is an eta-expanded version of the traditional
rule, and similar to the ABS rule of HOL\<close> and
the_eq_trivial: "(THE x. x = a) = (a::'a)"
axiomatization where
impI: "(P \<Longrightarrow> Q) \<Longrightarrow> P \<longrightarrow> Q" and
mp: "\<lbrakk>P \<longrightarrow> Q; P\<rbrakk> \<Longrightarrow> Q" and
iff: "(P \<longrightarrow> Q) \<longrightarrow> (Q \<longrightarrow> P) \<longrightarrow> (P = Q)" and
True_or_False: "(P = True) \<or> (P = False)"
definition If :: "bool \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'a" ("(if (_)/ then (_)/ else (_))" [0, 0, 10] 10)
where "If P x y \<equiv> (THE z::'a. (P = True \<longrightarrow> z = x) \<and> (P = False \<longrightarrow> z = y))"
definition Let :: "'a \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'b"
where "Let s f \<equiv> f s"
translations
"_Let (_binds b bs) e" \<rightleftharpoons> "_Let b (_Let bs e)"
"let x = a in e" \<rightleftharpoons> "CONST Let a (\<lambda>x. e)"
axiomatization undefined :: 'a
class default = fixes default :: 'a
subsection \<open>Fundamental rules\<close>
subsubsection \<open>Equality\<close>
lemma sym: "s = t \<Longrightarrow> t = s"
by (erule subst) (rule refl)
lemma ssubst: "t = s \<Longrightarrow> P s \<Longrightarrow> P t"
by (drule sym) (erule subst)
lemma trans: "\<lbrakk>r = s; s = t\<rbrakk> \<Longrightarrow> r = t"
by (erule subst)
lemma trans_sym [Pure.elim?]: "r = s \<Longrightarrow> t = s \<Longrightarrow> r = t"
by (rule trans [OF _ sym])
lemma meta_eq_to_obj_eq:
assumes "A \<equiv> B"
shows "A = B"
unfolding assms by (rule refl)
text \<open>Useful with \<open>erule\<close> for proving equalities from known equalities.\<close>
(* a = b
| |
c = d *)
lemma box_equals: "\<lbrakk>a = b; a = c; b = d\<rbrakk> \<Longrightarrow> c = d"
apply (rule trans)
apply (rule trans)
apply (rule sym)
apply assumption+
done
text \<open>For calculational reasoning:\<close>
lemma forw_subst: "a = b \<Longrightarrow> P b \<Longrightarrow> P a"
by (rule ssubst)
lemma back_subst: "P a \<Longrightarrow> a = b \<Longrightarrow> P b"
by (rule subst)
subsubsection \<open>Congruence rules for application\<close>
text \<open>Similar to \<open>AP_THM\<close> in Gordon's HOL.\<close>
lemma fun_cong: "(f :: 'a \<Rightarrow> 'b) = g \<Longrightarrow> f x = g x"
apply (erule subst)
apply (rule refl)
done
text \<open>Similar to \<open>AP_TERM\<close> in Gordon's HOL and FOL's \<open>subst_context\<close>.\<close>
lemma arg_cong: "x = y \<Longrightarrow> f x = f y"
apply (erule subst)
apply (rule refl)
done
lemma arg_cong2: "\<lbrakk>a = b; c = d\<rbrakk> \<Longrightarrow> f a c = f b d"
apply (erule ssubst)+
apply (rule refl)
done
lemma cong: "\<lbrakk>f = g; (x::'a) = y\<rbrakk> \<Longrightarrow> f x = g y"
apply (erule subst)+
apply (rule refl)
done
ML \<open>fun cong_tac ctxt = Cong_Tac.cong_tac ctxt @{thm cong}\<close>
subsubsection \<open>Equality of booleans -- iff\<close>
lemma iffI: assumes "P \<Longrightarrow> Q" and "Q \<Longrightarrow> P" shows "P = Q"
by (iprover intro: iff [THEN mp, THEN mp] impI assms)
lemma iffD2: "\<lbrakk>P = Q; Q\<rbrakk> \<Longrightarrow> P"
by (erule ssubst)
lemma rev_iffD2: "\<lbrakk>Q; P = Q\<rbrakk> \<Longrightarrow> P"
by (erule iffD2)
lemma iffD1: "Q = P \<Longrightarrow> Q \<Longrightarrow> P"
by (drule sym) (rule iffD2)
lemma rev_iffD1: "Q \<Longrightarrow> Q = P \<Longrightarrow> P"
by (drule sym) (rule rev_iffD2)
lemma iffE:
assumes major: "P = Q"
and minor: "\<lbrakk>P \<longrightarrow> Q; Q \<longrightarrow> P\<rbrakk> \<Longrightarrow> R"
shows R
by (iprover intro: minor impI major [THEN iffD2] major [THEN iffD1])
subsubsection \<open>True\<close>
lemma TrueI: True
unfolding True_def by (rule refl)
lemma eqTrueI: "P \<Longrightarrow> P = True"
by (iprover intro: iffI TrueI)
lemma eqTrueE: "P = True \<Longrightarrow> P"
by (erule iffD2) (rule TrueI)
subsubsection \<open>Universal quantifier\<close>
lemma allI:
assumes "\<And>x::'a. P x"
shows "\<forall>x. P x"
unfolding All_def by (iprover intro: ext eqTrueI assms)
lemma spec: "\<forall>x::'a. P x \<Longrightarrow> P x"
apply (unfold All_def)
apply (rule eqTrueE)
apply (erule fun_cong)
done
lemma allE:
assumes major: "\<forall>x. P x"
and minor: "P x \<Longrightarrow> R"
shows R
by (iprover intro: minor major [THEN spec])
lemma all_dupE:
assumes major: "\<forall>x. P x"
and minor: "\<lbrakk>P x; \<forall>x. P x\<rbrakk> \<Longrightarrow> R"
shows R
by (iprover intro: minor major major [THEN spec])
subsubsection \<open>False\<close>
text \<open>
Depends upon \<open>spec\<close>; it is impossible to do propositional
logic before quantifiers!
\<close>
lemma FalseE: "False \<Longrightarrow> P"
apply (unfold False_def)
apply (erule spec)
done
lemma False_neq_True: "False = True \<Longrightarrow> P"
by (erule eqTrueE [THEN FalseE])
subsubsection \<open>Negation\<close>
lemma notI:
assumes "P \<Longrightarrow> False"
shows "\<not> P"
apply (unfold not_def)
apply (iprover intro: impI assms)
done
lemma False_not_True: "False \<noteq> True"
apply (rule notI)
apply (erule False_neq_True)
done
lemma True_not_False: "True \<noteq> False"
apply (rule notI)
apply (drule sym)
apply (erule False_neq_True)
done
lemma notE: "\<lbrakk>\<not> P; P\<rbrakk> \<Longrightarrow> R"
apply (unfold not_def)
apply (erule mp [THEN FalseE])
apply assumption
done
lemma notI2: "(P \<Longrightarrow> \<not> Pa) \<Longrightarrow> (P \<Longrightarrow> Pa) \<Longrightarrow> \<not> P"
by (erule notE [THEN notI]) (erule meta_mp)
subsubsection \<open>Implication\<close>
lemma impE:
assumes "P \<longrightarrow> Q" P "Q \<Longrightarrow> R"
shows R
by (iprover intro: assms mp)
text \<open>Reduces \<open>Q\<close> to \<open>P \<longrightarrow> Q\<close>, allowing substitution in \<open>P\<close>.\<close>
lemma rev_mp: "\<lbrakk>P; P \<longrightarrow> Q\<rbrakk> \<Longrightarrow> Q"
by (iprover intro: mp)
lemma contrapos_nn:
assumes major: "\<not> Q"
and minor: "P \<Longrightarrow> Q"
shows "\<not> P"
by (iprover intro: notI minor major [THEN notE])
text \<open>Not used at all, but we already have the other 3 combinations.\<close>
lemma contrapos_pn:
assumes major: "Q"
and minor: "P \<Longrightarrow> \<not> Q"
shows "\<not> P"
by (iprover intro: notI minor major notE)
lemma not_sym: "t \<noteq> s \<Longrightarrow> s \<noteq> t"
by (erule contrapos_nn) (erule sym)
lemma eq_neq_eq_imp_neq: "\<lbrakk>x = a; a \<noteq> b; b = y\<rbrakk> \<Longrightarrow> x \<noteq> y"
by (erule subst, erule ssubst, assumption)
subsubsection \<open>Existential quantifier\<close>
lemma exI: "P x \<Longrightarrow> \<exists>x::'a. P x"
unfolding Ex_def by (iprover intro: allI allE impI mp)
lemma exE:
assumes major: "\<exists>x::'a. P x"
and minor: "\<And>x. P x \<Longrightarrow> Q"
shows "Q"
by (rule major [unfolded Ex_def, THEN spec, THEN mp]) (iprover intro: impI [THEN allI] minor)
subsubsection \<open>Conjunction\<close>
lemma conjI: "\<lbrakk>P; Q\<rbrakk> \<Longrightarrow> P \<and> Q"
unfolding and_def by (iprover intro: impI [THEN allI] mp)
lemma conjunct1: "\<lbrakk>P \<and> Q\<rbrakk> \<Longrightarrow> P"
unfolding and_def by (iprover intro: impI dest: spec mp)
lemma conjunct2: "\<lbrakk>P \<and> Q\<rbrakk> \<Longrightarrow> Q"
unfolding and_def by (iprover intro: impI dest: spec mp)
lemma conjE:
assumes major: "P \<and> Q"
and minor: "\<lbrakk>P; Q\<rbrakk> \<Longrightarrow> R"
shows R
apply (rule minor)
apply (rule major [THEN conjunct1])
apply (rule major [THEN conjunct2])
done
lemma context_conjI:
assumes P "P \<Longrightarrow> Q"
shows "P \<and> Q"
by (iprover intro: conjI assms)
subsubsection \<open>Disjunction\<close>
lemma disjI1: "P \<Longrightarrow> P \<or> Q"
unfolding or_def by (iprover intro: allI impI mp)
lemma disjI2: "Q \<Longrightarrow> P \<or> Q"
unfolding or_def by (iprover intro: allI impI mp)
lemma disjE:
assumes major: "P \<or> Q"
and minorP: "P \<Longrightarrow> R"
and minorQ: "Q \<Longrightarrow> R"
shows R
by (iprover intro: minorP minorQ impI
major [unfolded or_def, THEN spec, THEN mp, THEN mp])
subsubsection \<open>Classical logic\<close>
lemma classical:
assumes prem: "\<not> P \<Longrightarrow> P"
shows P
apply (rule True_or_False [THEN disjE, THEN eqTrueE])
apply assumption
apply (rule notI [THEN prem, THEN eqTrueI])
apply (erule subst)
apply assumption
done
lemmas ccontr = FalseE [THEN classical]
text \<open>\<open>notE\<close> with premises exchanged; it discharges \<open>\<not> R\<close> so that it can be used to
make elimination rules.\<close>
lemma rev_notE:
assumes premp: P
and premnot: "\<not> R \<Longrightarrow> \<not> P"
shows R
apply (rule ccontr)
apply (erule notE [OF premnot premp])
done
text \<open>Double negation law.\<close>
lemma notnotD: "\<not>\<not> P \<Longrightarrow> P"
apply (rule classical)
apply (erule notE)
apply assumption
done
lemma contrapos_pp:
assumes p1: Q
and p2: "\<not> P \<Longrightarrow> \<not> Q"
shows P
by (iprover intro: classical p1 p2 notE)
subsubsection \<open>Unique existence\<close>
lemma ex1I:
assumes "P a" "\<And>x. P x \<Longrightarrow> x = a"
shows "\<exists>!x. P x"
unfolding Ex1_def by (iprover intro: assms exI conjI allI impI)
text \<open>Sometimes easier to use: the premises have no shared variables. Safe!\<close>
lemma ex_ex1I:
assumes ex_prem: "\<exists>x. P x"
and eq: "\<And>x y. \<lbrakk>P x; P y\<rbrakk> \<Longrightarrow> x = y"
shows "\<exists>!x. P x"
by (iprover intro: ex_prem [THEN exE] ex1I eq)
lemma ex1E:
assumes major: "\<exists>!x. P x"
and minor: "\<And>x. \<lbrakk>P x; \<forall>y. P y \<longrightarrow> y = x\<rbrakk> \<Longrightarrow> R"
shows R
apply (rule major [unfolded Ex1_def, THEN exE])
apply (erule conjE)
apply (iprover intro: minor)
done
lemma ex1_implies_ex: "\<exists>!x. P x \<Longrightarrow> \<exists>x. P x"
apply (erule ex1E)
apply (rule exI)
apply assumption
done
subsubsection \<open>Classical intro rules for disjunction and existential quantifiers\<close>
lemma disjCI:
assumes "\<not> Q \<Longrightarrow> P"
shows "P \<or> Q"
by (rule classical) (iprover intro: assms disjI1 disjI2 notI elim: notE)
lemma excluded_middle: "\<not> P \<or> P"
by (iprover intro: disjCI)
text \<open>
case distinction as a natural deduction rule.
Note that \<open>\<not> P\<close> is the second case, not the first.
\<close>
lemma case_split [case_names True False]:
assumes prem1: "P \<Longrightarrow> Q"
and prem2: "\<not> P \<Longrightarrow> Q"
shows Q
apply (rule excluded_middle [THEN disjE])
apply (erule prem2)
apply (erule prem1)
done
text \<open>Classical implies (\<open>\<longrightarrow>\<close>) elimination.\<close>
lemma impCE:
assumes major: "P \<longrightarrow> Q"
and minor: "\<not> P \<Longrightarrow> R" "Q \<Longrightarrow> R"
shows R
apply (rule excluded_middle [of P, THEN disjE])
apply (iprover intro: minor major [THEN mp])+
done
text \<open>
This version of \<open>\<longrightarrow>\<close> elimination works on \<open>Q\<close> before \<open>P\<close>. It works best for
those cases in which \<open>P\<close> holds "almost everywhere". Can't install as
default: would break old proofs.
\<close>
lemma impCE':
assumes major: "P \<longrightarrow> Q"
and minor: "Q \<Longrightarrow> R" "\<not> P \<Longrightarrow> R"
shows R
apply (rule excluded_middle [of P, THEN disjE])
apply (iprover intro: minor major [THEN mp])+
done
text \<open>Classical \<open>\<longleftrightarrow>\<close> elimination.\<close>
lemma iffCE:
assumes major: "P = Q"
and minor: "\<lbrakk>P; Q\<rbrakk> \<Longrightarrow> R" "\<lbrakk>\<not> P; \<not> Q\<rbrakk> \<Longrightarrow> R"
shows R
by (rule major [THEN iffE]) (iprover intro: minor elim: impCE notE)
lemma exCI:
assumes "\<forall>x. \<not> P x \<Longrightarrow> P a"
shows "\<exists>x. P x"
by (rule ccontr) (iprover intro: assms exI allI notI notE [of "\<exists>x. P x"])
subsubsection \<open>Intuitionistic Reasoning\<close>
lemma impE':
assumes 1: "P \<longrightarrow> Q"
and 2: "Q \<Longrightarrow> R"
and 3: "P \<longrightarrow> Q \<Longrightarrow> P"
shows R
proof -
from 3 and 1 have P .
with 1 have Q by (rule impE)
with 2 show R .
qed
lemma allE':
assumes 1: "\<forall>x. P x"
and 2: "P x \<Longrightarrow> \<forall>x. P x \<Longrightarrow> Q"
shows Q
proof -
from 1 have "P x" by (rule spec)
from this and 1 show Q by (rule 2)
qed
lemma notE':
assumes 1: "\<not> P"
and 2: "\<not> P \<Longrightarrow> P"
shows R
proof -
from 2 and 1 have P .
with 1 show R by (rule notE)
qed
lemma TrueE: "True \<Longrightarrow> P \<Longrightarrow> P" .
lemma notFalseE: "\<not> False \<Longrightarrow> P \<Longrightarrow> P" .
lemmas [Pure.elim!] = disjE iffE FalseE conjE exE TrueE notFalseE
and [Pure.intro!] = iffI conjI impI TrueI notI allI refl
and [Pure.elim 2] = allE notE' impE'
and [Pure.intro] = exI disjI2 disjI1
lemmas [trans] = trans
and [sym] = sym not_sym
and [Pure.elim?] = iffD1 iffD2 impE
subsubsection \<open>Atomizing meta-level connectives\<close>
axiomatization where
eq_reflection: "x = y \<Longrightarrow> x \<equiv> y" \<comment> \<open>admissible axiom\<close>
lemma atomize_all [atomize]: "(\<And>x. P x) \<equiv> Trueprop (\<forall>x. P x)"
proof
assume "\<And>x. P x"
then show "\<forall>x. P x" ..
next
assume "\<forall>x. P x"
then show "\<And>x. P x" by (rule allE)
qed
lemma atomize_imp [atomize]: "(A \<Longrightarrow> B) \<equiv> Trueprop (A \<longrightarrow> B)"
proof
assume r: "A \<Longrightarrow> B"
show "A \<longrightarrow> B" by (rule impI) (rule r)
next
assume "A \<longrightarrow> B" and A
then show B by (rule mp)
qed
lemma atomize_not: "(A \<Longrightarrow> False) \<equiv> Trueprop (\<not> A)"
proof
assume r: "A \<Longrightarrow> False"
show "\<not> A" by (rule notI) (rule r)
next
assume "\<not> A" and A
then show False by (rule notE)
qed
lemma atomize_eq [atomize, code]: "(x \<equiv> y) \<equiv> Trueprop (x = y)"
proof
assume "x \<equiv> y"
show "x = y" by (unfold \<open>x \<equiv> y\<close>) (rule refl)
next
assume "x = y"
then show "x \<equiv> y" by (rule eq_reflection)
qed
lemma atomize_conj [atomize]: "(A &&& B) \<equiv> Trueprop (A \<and> B)"
proof
assume conj: "A &&& B"
show "A \<and> B"
proof (rule conjI)
from conj show A by (rule conjunctionD1)
from conj show B by (rule conjunctionD2)
qed
next
assume conj: "A \<and> B"
show "A &&& B"
proof -
from conj show A ..
from conj show B ..
qed
qed
lemmas [symmetric, rulify] = atomize_all atomize_imp
and [symmetric, defn] = atomize_all atomize_imp atomize_eq
subsubsection \<open>Atomizing elimination rules\<close>
lemma atomize_exL[atomize_elim]: "(\<And>x. P x \<Longrightarrow> Q) \<equiv> ((\<exists>x. P x) \<Longrightarrow> Q)"
by rule iprover+
lemma atomize_conjL[atomize_elim]: "(A \<Longrightarrow> B \<Longrightarrow> C) \<equiv> (A \<and> B \<Longrightarrow> C)"
by rule iprover+
lemma atomize_disjL[atomize_elim]: "((A \<Longrightarrow> C) \<Longrightarrow> (B \<Longrightarrow> C) \<Longrightarrow> C) \<equiv> ((A \<or> B \<Longrightarrow> C) \<Longrightarrow> C)"
by rule iprover+
lemma atomize_elimL[atomize_elim]: "(\<And>B. (A \<Longrightarrow> B) \<Longrightarrow> B) \<equiv> Trueprop A" ..
subsection \<open>Package setup\<close>
ML_file "Tools/hologic.ML"
subsubsection \<open>Sledgehammer setup\<close>
text \<open>
Theorems blacklisted to Sledgehammer. These theorems typically produce clauses
that are prolific (match too many equality or membership literals) and relate to
seldom-used facts. Some duplicate other rules.
\<close>
named_theorems no_atp "theorems that should be filtered out by Sledgehammer"
subsubsection \<open>Classical Reasoner setup\<close>
lemma imp_elim: "P \<longrightarrow> Q \<Longrightarrow> (\<not> R \<Longrightarrow> P) \<Longrightarrow> (Q \<Longrightarrow> R) \<Longrightarrow> R"
by (rule classical) iprover
lemma swap: "\<not> P \<Longrightarrow> (\<not> R \<Longrightarrow> P) \<Longrightarrow> R"
by (rule classical) iprover
lemma thin_refl: "\<lbrakk>x = x; PROP W\<rbrakk> \<Longrightarrow> PROP W" .
ML \<open>
structure Hypsubst = Hypsubst
(
val dest_eq = HOLogic.dest_eq
val dest_Trueprop = HOLogic.dest_Trueprop
val dest_imp = HOLogic.dest_imp
val eq_reflection = @{thm eq_reflection}
val rev_eq_reflection = @{thm meta_eq_to_obj_eq}
val imp_intr = @{thm impI}
val rev_mp = @{thm rev_mp}
val subst = @{thm subst}
val sym = @{thm sym}
val thin_refl = @{thm thin_refl};
);
open Hypsubst;
structure Classical = Classical
(
val imp_elim = @{thm imp_elim}
val not_elim = @{thm notE}
val swap = @{thm swap}
val classical = @{thm classical}
val sizef = Drule.size_of_thm
val hyp_subst_tacs = [Hypsubst.hyp_subst_tac]
);
structure Basic_Classical: BASIC_CLASSICAL = Classical;
open Basic_Classical;
\<close>
setup \<open>
(*prevent substitution on bool*)
let
fun non_bool_eq (@{const_name HOL.eq}, Type (_, [T, _])) = T <> @{typ bool}
| non_bool_eq _ = false;
fun hyp_subst_tac' ctxt =
SUBGOAL (fn (goal, i) =>
if Term.exists_Const non_bool_eq goal
then Hypsubst.hyp_subst_tac ctxt i
else no_tac);
in
Context_Rules.addSWrapper (fn ctxt => fn tac => hyp_subst_tac' ctxt ORELSE' tac)
end
\<close>
declare iffI [intro!]
and notI [intro!]
and impI [intro!]
and disjCI [intro!]
and conjI [intro!]
and TrueI [intro!]
and refl [intro!]
declare iffCE [elim!]
and FalseE [elim!]
and impCE [elim!]
and disjE [elim!]
and conjE [elim!]
declare ex_ex1I [intro!]
and allI [intro!]
and exI [intro]
declare exE [elim!]
allE [elim]
ML \<open>val HOL_cs = claset_of @{context}\<close>
lemma contrapos_np: "\<not> Q \<Longrightarrow> (\<not> P \<Longrightarrow> Q) \<Longrightarrow> P"
apply (erule swap)
apply (erule (1) meta_mp)
done
declare ex_ex1I [rule del, intro! 2]
and ex1I [intro]
declare ext [intro]
lemmas [intro?] = ext
and [elim?] = ex1_implies_ex
text \<open>Better than \<open>ex1E\<close> for classical reasoner: needs no quantifier duplication!\<close>
lemma alt_ex1E [elim!]:
assumes major: "\<exists>!x. P x"
and prem: "\<And>x. \<lbrakk>P x; \<forall>y y'. P y \<and> P y' \<longrightarrow> y = y'\<rbrakk> \<Longrightarrow> R"
shows R
apply (rule ex1E [OF major])
apply (rule prem)
apply assumption
apply (rule allI)+
apply (tactic \<open>eresolve_tac @{context} [Classical.dup_elim @{context} @{thm allE}] 1\<close>)
apply iprover
done
ML \<open>
structure Blast = Blast
(
structure Classical = Classical
val Trueprop_const = dest_Const @{const Trueprop}
val equality_name = @{const_name HOL.eq}
val not_name = @{const_name Not}
val notE = @{thm notE}
val ccontr = @{thm ccontr}
val hyp_subst_tac = Hypsubst.blast_hyp_subst_tac
);
val blast_tac = Blast.blast_tac;
\<close>
subsubsection \<open>THE: definite description operator\<close>
lemma the_equality [intro]:
assumes "P a"
and "\<And>x. P x \<Longrightarrow> x = a"
shows "(THE x. P x) = a"
by (blast intro: assms trans [OF arg_cong [where f=The] the_eq_trivial])
lemma theI:
assumes "P a"
and "\<And>x. P x \<Longrightarrow> x = a"
shows "P (THE x. P x)"
by (iprover intro: assms the_equality [THEN ssubst])
lemma theI': "\<exists>!x. P x \<Longrightarrow> P (THE x. P x)"
by (blast intro: theI)
text \<open>Easier to apply than \<open>theI\<close>: only one occurrence of \<open>P\<close>.\<close>
lemma theI2:
assumes "P a" "\<And>x. P x \<Longrightarrow> x = a" "\<And>x. P x \<Longrightarrow> Q x"
shows "Q (THE x. P x)"
by (iprover intro: assms theI)
lemma the1I2:
assumes "\<exists>!x. P x" "\<And>x. P x \<Longrightarrow> Q x"
shows "Q (THE x. P x)"
by (iprover intro: assms(2) theI2[where P=P and Q=Q] ex1E[OF assms(1)] elim: allE impE)
lemma the1_equality [elim?]: "\<lbrakk>\<exists>!x. P x; P a\<rbrakk> \<Longrightarrow> (THE x. P x) = a"
by blast
lemma the_sym_eq_trivial: "(THE y. x = y) = x"
by blast
subsubsection \<open>Simplifier\<close>
lemma eta_contract_eq: "(\<lambda>s. f s) = f" ..
lemma simp_thms:
shows not_not: "(\<not> \<not> P) = P"
and Not_eq_iff: "((\<not> P) = (\<not> Q)) = (P = Q)"
and
"(P \<noteq> Q) = (P = (\<not> Q))"
"(P \<or> \<not>P) = True" "(\<not> P \<or> P) = True"
"(x = x) = True"
and not_True_eq_False [code]: "(\<not> True) = False"
and not_False_eq_True [code]: "(\<not> False) = True"
and
"(\<not> P) \<noteq> P" "P \<noteq> (\<not> P)"
"(True = P) = P"
and eq_True: "(P = True) = P"
and "(False = P) = (\<not> P)"
and eq_False: "(P = False) = (\<not> P)"
and
"(True \<longrightarrow> P) = P" "(False \<longrightarrow> P) = True"
"(P \<longrightarrow> True) = True" "(P \<longrightarrow> P) = True"
"(P \<longrightarrow> False) = (\<not> P)" "(P \<longrightarrow> \<not> P) = (\<not> P)"
"(P \<and> True) = P" "(True \<and> P) = P"
"(P \<and> False) = False" "(False \<and> P) = False"
"(P \<and> P) = P" "(P \<and> (P \<and> Q)) = (P \<and> Q)"
"(P \<and> \<not> P) = False" "(\<not> P \<and> P) = False"
"(P \<or> True) = True" "(True \<or> P) = True"
"(P \<or> False) = P" "(False \<or> P) = P"
"(P \<or> P) = P" "(P \<or> (P \<or> Q)) = (P \<or> Q)" and
"(\<forall>x. P) = P" "(\<exists>x. P) = P" "\<exists>x. x = t" "\<exists>x. t = x"
and
"\<And>P. (\<exists>x. x = t \<and> P x) = P t"
"\<And>P. (\<exists>x. t = x \<and> P x) = P t"
"\<And>P. (\<forall>x. x = t \<longrightarrow> P x) = P t"
"\<And>P. (\<forall>x. t = x \<longrightarrow> P x) = P t"
"(\<forall>x. x \<noteq> t) = False" "(\<forall>x. t \<noteq> x) = False"
by (blast, blast, blast, blast, blast, iprover+)
lemma disj_absorb: "A \<or> A \<longleftrightarrow> A"
by blast
lemma disj_left_absorb: "A \<or> (A \<or> B) \<longleftrightarrow> A \<or> B"
by blast
lemma conj_absorb: "A \<and> A \<longleftrightarrow> A"
by blast
lemma conj_left_absorb: "A \<and> (A \<and> B) \<longleftrightarrow> A \<and> B"
by blast
lemma eq_ac:
shows eq_commute: "a = b \<longleftrightarrow> b = a"
and iff_left_commute: "(P \<longleftrightarrow> (Q \<longleftrightarrow> R)) \<longleftrightarrow> (Q \<longleftrightarrow> (P \<longleftrightarrow> R))"
and iff_assoc: "((P \<longleftrightarrow> Q) \<longleftrightarrow> R) \<longleftrightarrow> (P \<longleftrightarrow> (Q \<longleftrightarrow> R))"
by (iprover, blast+)
lemma neq_commute: "a \<noteq> b \<longleftrightarrow> b \<noteq> a" by iprover
lemma conj_comms:
shows conj_commute: "P \<and> Q \<longleftrightarrow> Q \<and> P"
and conj_left_commute: "P \<and> (Q \<and> R) \<longleftrightarrow> Q \<and> (P \<and> R)" by iprover+
lemma conj_assoc: "(P \<and> Q) \<and> R \<longleftrightarrow> P \<and> (Q \<and> R)" by iprover
lemmas conj_ac = conj_commute conj_left_commute conj_assoc
lemma disj_comms:
shows disj_commute: "P \<or> Q \<longleftrightarrow> Q \<or> P"
and disj_left_commute: "P \<or> (Q \<or> R) \<longleftrightarrow> Q \<or> (P \<or> R)" by iprover+
lemma disj_assoc: "(P \<or> Q) \<or> R \<longleftrightarrow> P \<or> (Q \<or> R)" by iprover
lemmas disj_ac = disj_commute disj_left_commute disj_assoc
lemma conj_disj_distribL: "P \<and> (Q \<or> R) \<longleftrightarrow> P \<and> Q \<or> P \<and> R" by iprover
lemma conj_disj_distribR: "(P \<or> Q) \<and> R \<longleftrightarrow> P \<and> R \<or> Q \<and> R" by iprover
lemma disj_conj_distribL: "P \<or> (Q \<and> R) \<longleftrightarrow> (P \<or> Q) \<and> (P \<or> R)" by iprover
lemma disj_conj_distribR: "(P \<and> Q) \<or> R \<longleftrightarrow> (P \<or> R) \<and> (Q \<or> R)" by iprover
lemma imp_conjR: "(P \<longrightarrow> (Q \<and> R)) = ((P \<longrightarrow> Q) \<and> (P \<longrightarrow> R))" by iprover
lemma imp_conjL: "((P \<and> Q) \<longrightarrow> R) = (P \<longrightarrow> (Q \<longrightarrow> R))" by iprover
lemma imp_disjL: "((P \<or> Q) \<longrightarrow> R) = ((P \<longrightarrow> R) \<and> (Q \<longrightarrow> R))" by iprover
text \<open>These two are specialized, but \<open>imp_disj_not1\<close> is useful in \<open>Auth/Yahalom\<close>.\<close>
lemma imp_disj_not1: "(P \<longrightarrow> Q \<or> R) \<longleftrightarrow> (\<not> Q \<longrightarrow> P \<longrightarrow> R)" by blast
lemma imp_disj_not2: "(P \<longrightarrow> Q \<or> R) \<longleftrightarrow> (\<not> R \<longrightarrow> P \<longrightarrow> Q)" by blast
lemma imp_disj1: "((P \<longrightarrow> Q) \<or> R) \<longleftrightarrow> (P \<longrightarrow> Q \<or> R)" by blast
lemma imp_disj2: "(Q \<or> (P \<longrightarrow> R)) \<longleftrightarrow> (P \<longrightarrow> Q \<or> R)" by blast
lemma imp_cong: "(P = P') \<Longrightarrow> (P' \<Longrightarrow> (Q = Q')) \<Longrightarrow> ((P \<longrightarrow> Q) \<longleftrightarrow> (P' \<longrightarrow> Q'))"
by iprover
lemma de_Morgan_disj: "\<not> (P \<or> Q) \<longleftrightarrow> \<not> P \<and> \<not> Q" by iprover
lemma de_Morgan_conj: "\<not> (P \<and> Q) \<longleftrightarrow> \<not> P \<or> \<not> Q" by blast
lemma not_imp: "\<not> (P \<longrightarrow> Q) \<longleftrightarrow> P \<and> \<not> Q" by blast
lemma not_iff: "P \<noteq> Q \<longleftrightarrow> (P \<longleftrightarrow> \<not> Q)" by blast
lemma disj_not1: "\<not> P \<or> Q \<longleftrightarrow> (P \<longrightarrow> Q)" by blast
lemma disj_not2: "P \<or> \<not> Q \<longleftrightarrow> (Q \<longrightarrow> P)" by blast \<comment> \<open>changes orientation :-(\<close>
lemma imp_conv_disj: "(P \<longrightarrow> Q) \<longleftrightarrow> (\<not> P) \<or> Q" by blast
lemma disj_imp: "P \<or> Q \<longleftrightarrow> \<not> P \<longrightarrow> Q" by blast
lemma iff_conv_conj_imp: "(P \<longleftrightarrow> Q) \<longleftrightarrow> (P \<longrightarrow> Q) \<and> (Q \<longrightarrow> P)" by iprover
lemma cases_simp: "(P \<longrightarrow> Q) \<and> (\<not> P \<longrightarrow> Q) \<longleftrightarrow> Q"
\<comment> \<open>Avoids duplication of subgoals after \<open>if_split\<close>, when the true and false\<close>
\<comment> \<open>cases boil down to the same thing.\<close>
by blast
lemma not_all: "\<not> (\<forall>x. P x) \<longleftrightarrow> (\<exists>x. \<not> P x)" by blast
lemma imp_all: "((\<forall>x. P x) \<longrightarrow> Q) \<longleftrightarrow> (\<exists>x. P x \<longrightarrow> Q)" by blast
lemma not_ex: "\<not> (\<exists>x. P x) \<longleftrightarrow> (\<forall>x. \<not> P x)" by iprover
lemma imp_ex: "((\<exists>x. P x) \<longrightarrow> Q) \<longleftrightarrow> (\<forall>x. P x \<longrightarrow> Q)" by iprover
lemma all_not_ex: "(\<forall>x. P x) \<longleftrightarrow> \<not> (\<exists>x. \<not> P x)" by blast
declare All_def [no_atp]
lemma ex_disj_distrib: "(\<exists>x. P x \<or> Q x) \<longleftrightarrow> (\<exists>x. P x) \<or> (\<exists>x. Q x)" by iprover
lemma all_conj_distrib: "(\<forall>x. P x \<and> Q x) \<longleftrightarrow> (\<forall>x. P x) \<and> (\<forall>x. Q x)" by iprover
text \<open>
\<^medskip> The \<open>\<and>\<close> congruence rule: not included by default!
May slow rewrite proofs down by as much as 50\%\<close>
lemma conj_cong: "P = P' \<Longrightarrow> (P' \<Longrightarrow> Q = Q') \<Longrightarrow> (P \<and> Q) = (P' \<and> Q')"
by iprover
lemma rev_conj_cong: "Q = Q' \<Longrightarrow> (Q' \<Longrightarrow> P = P') \<Longrightarrow> (P \<and> Q) = (P' \<and> Q')"
by iprover
text \<open>The \<open>|\<close> congruence rule: not included by default!\<close>
lemma disj_cong: "P = P' \<Longrightarrow> (\<not> P' \<Longrightarrow> Q = Q') \<Longrightarrow> (P \<or> Q) = (P' \<or> Q')"
by blast
text \<open>\<^medskip> if-then-else rules\<close>
lemma if_True [code]: "(if True then x else y) = x"
unfolding If_def by blast
lemma if_False [code]: "(if False then x else y) = y"
unfolding If_def by blast
lemma if_P: "P \<Longrightarrow> (if P then x else y) = x"
unfolding If_def by blast
lemma if_not_P: "\<not> P \<Longrightarrow> (if P then x else y) = y"
unfolding If_def by blast
lemma if_split: "P (if Q then x else y) = ((Q \<longrightarrow> P x) \<and> (\<not> Q \<longrightarrow> P y))"
apply (rule case_split [of Q])
apply (simplesubst if_P)
prefer 3
apply (simplesubst if_not_P)
apply blast+
done
lemma if_split_asm: "P (if Q then x else y) = (\<not> ((Q \<and> \<not> P x) \<or> (\<not> Q \<and> \<not> P y)))"
by (simplesubst if_split) blast
lemmas if_splits [no_atp] = if_split if_split_asm
lemma if_cancel: "(if c then x else x) = x"
by (simplesubst if_split) blast
lemma if_eq_cancel: "(if x = y then y else x) = x"
by (simplesubst if_split) blast
lemma if_bool_eq_conj: "(if P then Q else R) = ((P \<longrightarrow> Q) \<and> (\<not> P \<longrightarrow> R))"
\<comment> \<open>This form is useful for expanding \<open>if\<close>s on the RIGHT of the \<open>\<Longrightarrow>\<close> symbol.\<close>
by (rule if_split)
lemma if_bool_eq_disj: "(if P then Q else R) = ((P \<and> Q) \<or> (\<not> P \<and> R))"
\<comment> \<open>And this form is useful for expanding \<open>if\<close>s on the LEFT.\<close>
by (simplesubst if_split) blast
lemma Eq_TrueI: "P \<Longrightarrow> P \<equiv> True" unfolding atomize_eq by iprover
lemma Eq_FalseI: "\<not> P \<Longrightarrow> P \<equiv> False" unfolding atomize_eq by iprover
text \<open>\<^medskip> let rules for simproc\<close>
lemma Let_folded: "f x \<equiv> g x \<Longrightarrow> Let x f \<equiv> Let x g"
by (unfold Let_def)
lemma Let_unfold: "f x \<equiv> g \<Longrightarrow> Let x f \<equiv> g"
by (unfold Let_def)
text \<open>
The following copy of the implication operator is useful for
fine-tuning congruence rules. It instructs the simplifier to simplify
its premise.
\<close>
definition simp_implies :: "prop \<Rightarrow> prop \<Rightarrow> prop" (infixr "=simp=>" 1)
where "simp_implies \<equiv> op \<Longrightarrow>"
lemma simp_impliesI:
assumes PQ: "(PROP P \<Longrightarrow> PROP Q)"
shows "PROP P =simp=> PROP Q"
apply (unfold simp_implies_def)
apply (rule PQ)
apply assumption
done
lemma simp_impliesE:
assumes PQ: "PROP P =simp=> PROP Q"
and P: "PROP P"
and QR: "PROP Q \<Longrightarrow> PROP R"
shows "PROP R"
apply (rule QR)
apply (rule PQ [unfolded simp_implies_def])
apply (rule P)
done
lemma simp_implies_cong:
assumes PP' :"PROP P \<equiv> PROP P'"
and P'QQ': "PROP P' \<Longrightarrow> (PROP Q \<equiv> PROP Q')"
shows "(PROP P =simp=> PROP Q) \<equiv> (PROP P' =simp=> PROP Q')"
unfolding simp_implies_def
proof (rule equal_intr_rule)
assume PQ: "PROP P \<Longrightarrow> PROP Q"
and P': "PROP P'"
from PP' [symmetric] and P' have "PROP P"
by (rule equal_elim_rule1)
then have "PROP Q" by (rule PQ)
with P'QQ' [OF P'] show "PROP Q'" by (rule equal_elim_rule1)
next
assume P'Q': "PROP P' \<Longrightarrow> PROP Q'"
and P: "PROP P"
from PP' and P have P': "PROP P'" by (rule equal_elim_rule1)
then have "PROP Q'" by (rule P'Q')
with P'QQ' [OF P', symmetric] show "PROP Q"
by (rule equal_elim_rule1)
qed
lemma uncurry:
assumes "P \<longrightarrow> Q \<longrightarrow> R"
shows "P \<and> Q \<longrightarrow> R"
using assms by blast
lemma iff_allI:
assumes "\<And>x. P x = Q x"
shows "(\<forall>x. P x) = (\<forall>x. Q x)"
using assms by blast
lemma iff_exI:
assumes "\<And>x. P x = Q x"
shows "(\<exists>x. P x) = (\<exists>x. Q x)"
using assms by blast
lemma all_comm: "(\<forall>x y. P x y) = (\<forall>y x. P x y)"
by blast
lemma ex_comm: "(\<exists>x y. P x y) = (\<exists>y x. P x y)"
by blast
ML_file "Tools/simpdata.ML"
ML \<open>open Simpdata\<close>
setup \<open>
map_theory_simpset (put_simpset HOL_basic_ss) #>
Simplifier.method_setup Splitter.split_modifiers
\<close>
simproc_setup defined_Ex ("\<exists>x. P x") = \<open>fn _ => Quantifier1.rearrange_ex\<close>
simproc_setup defined_All ("\<forall>x. P x") = \<open>fn _ => Quantifier1.rearrange_all\<close>
text \<open>Simproc for proving \<open>(y = x) \<equiv> False\<close> from premise \<open>\<not> (x = y)\<close>:\<close>
simproc_setup neq ("x = y") = \<open>fn _ =>
let
val neq_to_EQ_False = @{thm not_sym} RS @{thm Eq_FalseI};
fun is_neq eq lhs rhs thm =
(case Thm.prop_of thm of
_ $ (Not $ (eq' $ l' $ r')) =>
Not = HOLogic.Not andalso eq' = eq andalso
r' aconv lhs andalso l' aconv rhs
| _ => false);
fun proc ss ct =
(case Thm.term_of ct of
eq $ lhs $ rhs =>
(case find_first (is_neq eq lhs rhs) (Simplifier.prems_of ss) of
SOME thm => SOME (thm RS neq_to_EQ_False)
| NONE => NONE)
| _ => NONE);
in proc end;
\<close>
simproc_setup let_simp ("Let x f") = \<open>
let
fun count_loose (Bound i) k = if i >= k then 1 else 0
| count_loose (s $ t) k = count_loose s k + count_loose t k
| count_loose (Abs (_, _, t)) k = count_loose t (k + 1)
| count_loose _ _ = 0;
fun is_trivial_let (Const (@{const_name Let}, _) $ x $ t) =
(case t of
Abs (_, _, t') => count_loose t' 0 <= 1
| _ => true);
in
fn _ => fn ctxt => fn ct =>
if is_trivial_let (Thm.term_of ct)
then SOME @{thm Let_def} (*no or one ocurrence of bound variable*)
else
let (*Norbert Schirmer's case*)
val t = Thm.term_of ct;
val ([t'], ctxt') = Variable.import_terms false [t] ctxt;
in
Option.map (hd o Variable.export ctxt' ctxt o single)
(case t' of Const (@{const_name Let},_) $ x $ f => (* x and f are already in normal form *)
if is_Free x orelse is_Bound x orelse is_Const x
then SOME @{thm Let_def}
else
let
val n = case f of (Abs (x, _, _)) => x | _ => "x";
val cx = Thm.cterm_of ctxt x;
val xT = Thm.typ_of_cterm cx;
val cf = Thm.cterm_of ctxt f;
val fx_g = Simplifier.rewrite ctxt (Thm.apply cf cx);
val (_ $ _ $ g) = Thm.prop_of fx_g;
val g' = abstract_over (x, g);
val abs_g'= Abs (n, xT, g');
in
if g aconv g' then
let
val rl =
infer_instantiate ctxt [(("f", 0), cf), (("x", 0), cx)] @{thm Let_unfold};
in SOME (rl OF [fx_g]) end
else if (Envir.beta_eta_contract f) aconv (Envir.beta_eta_contract abs_g')
then NONE (*avoid identity conversion*)
else
let
val g'x = abs_g' $ x;
val g_g'x = Thm.symmetric (Thm.beta_conversion false (Thm.cterm_of ctxt g'x));
val rl =
@{thm Let_folded} |> infer_instantiate ctxt
[(("f", 0), Thm.cterm_of ctxt f),
(("x", 0), cx),
(("g", 0), Thm.cterm_of ctxt abs_g')];
in SOME (rl OF [Thm.transitive fx_g g_g'x]) end
end
| _ => NONE)
end
end
\<close>
lemma True_implies_equals: "(True \<Longrightarrow> PROP P) \<equiv> PROP P"
proof
assume "True \<Longrightarrow> PROP P"
from this [OF TrueI] show "PROP P" .
next
assume "PROP P"
then show "PROP P" .
qed
lemma implies_True_equals: "(PROP P \<Longrightarrow> True) \<equiv> Trueprop True"
by standard (intro TrueI)
lemma False_implies_equals: "(False \<Longrightarrow> P) \<equiv> Trueprop True"
by standard simp_all
(* This is not made a simp rule because it does not improve any proofs
but slows some AFP entries down by 5% (cpu time). May 2015 *)
lemma implies_False_swap:
"NO_MATCH (Trueprop False) P \<Longrightarrow>
(False \<Longrightarrow> PROP P \<Longrightarrow> PROP Q) \<equiv> (PROP P \<Longrightarrow> False \<Longrightarrow> PROP Q)"
by (rule swap_prems_eq)
lemma ex_simps:
"\<And>P Q. (\<exists>x. P x \<and> Q) = ((\<exists>x. P x) \<and> Q)"
"\<And>P Q. (\<exists>x. P \<and> Q x) = (P \<and> (\<exists>x. Q x))"
"\<And>P Q. (\<exists>x. P x \<or> Q) = ((\<exists>x. P x) \<or> Q)"
"\<And>P Q. (\<exists>x. P \<or> Q x) = (P \<or> (\<exists>x. Q x))"
"\<And>P Q. (\<exists>x. P x \<longrightarrow> Q) = ((\<forall>x. P x) \<longrightarrow> Q)"
"\<And>P Q. (\<exists>x. P \<longrightarrow> Q x) = (P \<longrightarrow> (\<exists>x. Q x))"
\<comment> \<open>Miniscoping: pushing in existential quantifiers.\<close>
by (iprover | blast)+
lemma all_simps:
"\<And>P Q. (\<forall>x. P x \<and> Q) = ((\<forall>x. P x) \<and> Q)"
"\<And>P Q. (\<forall>x. P \<and> Q x) = (P \<and> (\<forall>x. Q x))"
"\<And>P Q. (\<forall>x. P x \<or> Q) = ((\<forall>x. P x) \<or> Q)"
"\<And>P Q. (\<forall>x. P \<or> Q x) = (P \<or> (\<forall>x. Q x))"
"\<And>P Q. (\<forall>x. P x \<longrightarrow> Q) = ((\<exists>x. P x) \<longrightarrow> Q)"
"\<And>P Q. (\<forall>x. P \<longrightarrow> Q x) = (P \<longrightarrow> (\<forall>x. Q x))"
\<comment> \<open>Miniscoping: pushing in universal quantifiers.\<close>
by (iprover | blast)+
lemmas [simp] =
triv_forall_equality \<comment> \<open>prunes params\<close>
True_implies_equals implies_True_equals \<comment> \<open>prune \<open>True\<close> in asms\<close>
False_implies_equals \<comment> \<open>prune \<open>False\<close> in asms\<close>
if_True
if_False
if_cancel
if_eq_cancel
imp_disjL \<comment>
\<open>In general it seems wrong to add distributive laws by default: they
might cause exponential blow-up. But \<open>imp_disjL\<close> has been in for a while
and cannot be removed without affecting existing proofs. Moreover,
rewriting by \<open>(P \<or> Q \<longrightarrow> R) = ((P \<longrightarrow> R) \<and> (Q \<longrightarrow> R))\<close> might be justified on the
grounds that it allows simplification of \<open>R\<close> in the two cases.\<close>
conj_assoc
disj_assoc
de_Morgan_conj
de_Morgan_disj
imp_disj1
imp_disj2
not_imp
disj_not1
not_all
not_ex
cases_simp
the_eq_trivial
the_sym_eq_trivial
ex_simps
all_simps
simp_thms
lemmas [cong] = imp_cong simp_implies_cong
lemmas [split] = if_split
ML \<open>val HOL_ss = simpset_of @{context}\<close>
text \<open>Simplifies \<open>x\<close> assuming \<open>c\<close> and \<open>y\<close> assuming \<open>\<not> c\<close>.\<close>
lemma if_cong:
assumes "b = c"
and "c \<Longrightarrow> x = u"
and "\<not> c \<Longrightarrow> y = v"
shows "(if b then x else y) = (if c then u else v)"
using assms by simp
text \<open>Prevents simplification of \<open>x\<close> and \<open>y\<close>:
faster and allows the execution of functional programs.\<close>
lemma if_weak_cong [cong]:
assumes "b = c"
shows "(if b then x else y) = (if c then x else y)"
using assms by (rule arg_cong)
text \<open>Prevents simplification of t: much faster\<close>
lemma let_weak_cong:
assumes "a = b"
shows "(let x = a in t x) = (let x = b in t x)"
using assms by (rule arg_cong)
text \<open>To tidy up the result of a simproc. Only the RHS will be simplified.\<close>
lemma eq_cong2:
assumes "u = u'"
shows "(t \<equiv> u) \<equiv> (t \<equiv> u')"
using assms by simp
lemma if_distrib: "f (if c then x else y) = (if c then f x else f y)"
by simp
text \<open>As a simplification rule, it replaces all function equalities by
first-order equalities.\<close>
lemma fun_eq_iff: "f = g \<longleftrightarrow> (\<forall>x. f x = g x)"
by auto
subsubsection \<open>Generic cases and induction\<close>
text \<open>Rule projections:\<close>
ML \<open>
structure Project_Rule = Project_Rule
(
val conjunct1 = @{thm conjunct1}
val conjunct2 = @{thm conjunct2}
val mp = @{thm mp}
);
\<close>
context
begin
qualified definition "induct_forall P \<equiv> \<forall>x. P x"
qualified definition "induct_implies A B \<equiv> A \<longrightarrow> B"
qualified definition "induct_equal x y \<equiv> x = y"
qualified definition "induct_conj A B \<equiv> A \<and> B"
qualified definition "induct_true \<equiv> True"
qualified definition "induct_false \<equiv> False"
lemma induct_forall_eq: "(\<And>x. P x) \<equiv> Trueprop (induct_forall (\<lambda>x. P x))"
by (unfold atomize_all induct_forall_def)
lemma induct_implies_eq: "(A \<Longrightarrow> B) \<equiv> Trueprop (induct_implies A B)"
by (unfold atomize_imp induct_implies_def)
lemma induct_equal_eq: "(x \<equiv> y) \<equiv> Trueprop (induct_equal x y)"
by (unfold atomize_eq induct_equal_def)
lemma induct_conj_eq: "(A &&& B) \<equiv> Trueprop (induct_conj A B)"
by (unfold atomize_conj induct_conj_def)
lemmas induct_atomize' = induct_forall_eq induct_implies_eq induct_conj_eq
lemmas induct_atomize = induct_atomize' induct_equal_eq
lemmas induct_rulify' [symmetric] = induct_atomize'
lemmas induct_rulify [symmetric] = induct_atomize
lemmas induct_rulify_fallback =
induct_forall_def induct_implies_def induct_equal_def induct_conj_def
induct_true_def induct_false_def
lemma induct_forall_conj: "induct_forall (\<lambda>x. induct_conj (A x) (B x)) =
induct_conj (induct_forall A) (induct_forall B)"
by (unfold induct_forall_def induct_conj_def) iprover
lemma induct_implies_conj: "induct_implies C (induct_conj A B) =
induct_conj (induct_implies C A) (induct_implies C B)"
by (unfold induct_implies_def induct_conj_def) iprover
lemma induct_conj_curry: "(induct_conj A B \<Longrightarrow> PROP C) \<equiv> (A \<Longrightarrow> B \<Longrightarrow> PROP C)"
proof
assume r: "induct_conj A B \<Longrightarrow> PROP C"
assume ab: A B
show "PROP C" by (rule r) (simp add: induct_conj_def ab)
next
assume r: "A \<Longrightarrow> B \<Longrightarrow> PROP C"
assume ab: "induct_conj A B"
show "PROP C" by (rule r) (simp_all add: ab [unfolded induct_conj_def])
qed
lemmas induct_conj = induct_forall_conj induct_implies_conj induct_conj_curry
lemma induct_trueI: "induct_true"
by (simp add: induct_true_def)
text \<open>Method setup.\<close>
ML_file "~~/src/Tools/induct.ML"
ML \<open>
structure Induct = Induct
(
val cases_default = @{thm case_split}
val atomize = @{thms induct_atomize}
val rulify = @{thms induct_rulify'}
val rulify_fallback = @{thms induct_rulify_fallback}
val equal_def = @{thm induct_equal_def}
fun dest_def (Const (@{const_name induct_equal}, _) $ t $ u) = SOME (t, u)
| dest_def _ = NONE
fun trivial_tac ctxt = match_tac ctxt @{thms induct_trueI}
)
\<close>
ML_file "~~/src/Tools/induction.ML"
declaration \<open>
fn _ => Induct.map_simpset (fn ss => ss
addsimprocs
[Simplifier.make_simproc @{context} "swap_induct_false"
{lhss = [@{term "induct_false \<Longrightarrow> PROP P \<Longrightarrow> PROP Q"}],
proc = fn _ => fn _ => fn ct =>
(case Thm.term_of ct of
_ $ (P as _ $ @{const induct_false}) $ (_ $ Q $ _) =>
if P <> Q then SOME Drule.swap_prems_eq else NONE
| _ => NONE)},
Simplifier.make_simproc @{context} "induct_equal_conj_curry"
{lhss = [@{term "induct_conj P Q \<Longrightarrow> PROP R"}],
proc = fn _ => fn _ => fn ct =>
(case Thm.term_of ct of
_ $ (_ $ P) $ _ =>
let
fun is_conj (@{const induct_conj} $ P $ Q) =
is_conj P andalso is_conj Q
| is_conj (Const (@{const_name induct_equal}, _) $ _ $ _) = true
| is_conj @{const induct_true} = true
| is_conj @{const induct_false} = true
| is_conj _ = false
in if is_conj P then SOME @{thm induct_conj_curry} else NONE end
| _ => NONE)}]
|> Simplifier.set_mksimps (fn ctxt =>
Simpdata.mksimps Simpdata.mksimps_pairs ctxt #>
map (rewrite_rule ctxt (map Thm.symmetric @{thms induct_rulify_fallback}))))
\<close>
text \<open>Pre-simplification of induction and cases rules\<close>
lemma [induct_simp]: "(\<And>x. induct_equal x t \<Longrightarrow> PROP P x) \<equiv> PROP P t"
unfolding induct_equal_def
proof
assume r: "\<And>x. x = t \<Longrightarrow> PROP P x"
show "PROP P t" by (rule r [OF refl])
next
fix x
assume "PROP P t" "x = t"
then show "PROP P x" by simp
qed
lemma [induct_simp]: "(\<And>x. induct_equal t x \<Longrightarrow> PROP P x) \<equiv> PROP P t"
unfolding induct_equal_def
proof
assume r: "\<And>x. t = x \<Longrightarrow> PROP P x"
show "PROP P t" by (rule r [OF refl])
next
fix x
assume "PROP P t" "t = x"
then show "PROP P x" by simp
qed
lemma [induct_simp]: "(induct_false \<Longrightarrow> P) \<equiv> Trueprop induct_true"
unfolding induct_false_def induct_true_def
by (iprover intro: equal_intr_rule)
lemma [induct_simp]: "(induct_true \<Longrightarrow> PROP P) \<equiv> PROP P"
unfolding induct_true_def
proof
assume "True \<Longrightarrow> PROP P"
then show "PROP P" using TrueI .
next
assume "PROP P"
then show "PROP P" .
qed
lemma [induct_simp]: "(PROP P \<Longrightarrow> induct_true) \<equiv> Trueprop induct_true"
unfolding induct_true_def
by (iprover intro: equal_intr_rule)
lemma [induct_simp]: "(\<And>x::'a::{}. induct_true) \<equiv> Trueprop induct_true"
unfolding induct_true_def
by (iprover intro: equal_intr_rule)
lemma [induct_simp]: "induct_implies induct_true P \<equiv> P"
by (simp add: induct_implies_def induct_true_def)
lemma [induct_simp]: "x = x \<longleftrightarrow> True"
by (rule simp_thms)
end
ML_file "~~/src/Tools/induct_tacs.ML"
subsubsection \<open>Coherent logic\<close>
ML_file "~~/src/Tools/coherent.ML"
ML \<open>
structure Coherent = Coherent
(
val atomize_elimL = @{thm atomize_elimL};
val atomize_exL = @{thm atomize_exL};
val atomize_conjL = @{thm atomize_conjL};
val atomize_disjL = @{thm atomize_disjL};
val operator_names = [@{const_name HOL.disj}, @{const_name HOL.conj}, @{const_name Ex}];
);
\<close>
subsubsection \<open>Reorienting equalities\<close>
ML \<open>
signature REORIENT_PROC =
sig
val add : (term -> bool) -> theory -> theory
val proc : morphism -> Proof.context -> cterm -> thm option
end;
structure Reorient_Proc : REORIENT_PROC =
struct
structure Data = Theory_Data
(
type T = ((term -> bool) * stamp) list;
val empty = [];
val extend = I;
fun merge data : T = Library.merge (eq_snd op =) data;
);
fun add m = Data.map (cons (m, stamp ()));
fun matches thy t = exists (fn (m, _) => m t) (Data.get thy);
val meta_reorient = @{thm eq_commute [THEN eq_reflection]};
fun proc phi ctxt ct =
let
val thy = Proof_Context.theory_of ctxt;
in
case Thm.term_of ct of
(_ $ t $ u) => if matches thy u then NONE else SOME meta_reorient
| _ => NONE
end;
end;
\<close>
subsection \<open>Other simple lemmas and lemma duplicates\<close>
lemma ex1_eq [iff]: "\<exists>!x. x = t" "\<exists>!x. t = x"
by blast+
lemma choice_eq: "(\<forall>x. \<exists>!y. P x y) = (\<exists>!f. \<forall>x. P x (f x))"
apply (rule iffI)
apply (rule_tac a = "\<lambda>x. THE y. P x y" in ex1I)
apply (fast dest!: theI')
apply (fast intro: the1_equality [symmetric])
apply (erule ex1E)
apply (rule allI)
apply (rule ex1I)
apply (erule spec)
apply (erule_tac x = "\<lambda>z. if z = x then y else f z" in allE)
apply (erule impE)
apply (rule allI)
apply (case_tac "xa = x")
apply (drule_tac [3] x = x in fun_cong)
apply simp_all
done
lemmas eq_sym_conv = eq_commute
lemma nnf_simps:
"(\<not> (P \<and> Q)) = (\<not> P \<or> \<not> Q)"
"(\<not> (P \<or> Q)) = (\<not> P \<and> \<not> Q)"
"(P \<longrightarrow> Q) = (\<not> P \<or> Q)"
"(P = Q) = ((P \<and> Q) \<or> (\<not> P \<and> \<not> Q))"
"(\<not> (P = Q)) = ((P \<and> \<not> Q) \<or> (\<not> P \<and> Q))"
"(\<not> \<not> P) = P"
by blast+
subsection \<open>Basic ML bindings\<close>
ML \<open>
val FalseE = @{thm FalseE}
val Let_def = @{thm Let_def}
val TrueI = @{thm TrueI}
val allE = @{thm allE}
val allI = @{thm allI}
val all_dupE = @{thm all_dupE}
val arg_cong = @{thm arg_cong}
val box_equals = @{thm box_equals}
val ccontr = @{thm ccontr}
val classical = @{thm classical}
val conjE = @{thm conjE}
val conjI = @{thm conjI}
val conjunct1 = @{thm conjunct1}
val conjunct2 = @{thm conjunct2}
val disjCI = @{thm disjCI}
val disjE = @{thm disjE}
val disjI1 = @{thm disjI1}
val disjI2 = @{thm disjI2}
val eq_reflection = @{thm eq_reflection}
val ex1E = @{thm ex1E}
val ex1I = @{thm ex1I}
val ex1_implies_ex = @{thm ex1_implies_ex}
val exE = @{thm exE}
val exI = @{thm exI}
val excluded_middle = @{thm excluded_middle}
val ext = @{thm ext}
val fun_cong = @{thm fun_cong}
val iffD1 = @{thm iffD1}
val iffD2 = @{thm iffD2}
val iffI = @{thm iffI}
val impE = @{thm impE}
val impI = @{thm impI}
val meta_eq_to_obj_eq = @{thm meta_eq_to_obj_eq}
val mp = @{thm mp}
val notE = @{thm notE}
val notI = @{thm notI}
val not_all = @{thm not_all}
val not_ex = @{thm not_ex}
val not_iff = @{thm not_iff}
val not_not = @{thm not_not}
val not_sym = @{thm not_sym}
val refl = @{thm refl}
val rev_mp = @{thm rev_mp}
val spec = @{thm spec}
val ssubst = @{thm ssubst}
val subst = @{thm subst}
val sym = @{thm sym}
val trans = @{thm trans}
\<close>
ML_file "Tools/cnf.ML"
section \<open>\<open>NO_MATCH\<close> simproc\<close>
text \<open>
The simplification procedure can be used to avoid simplification of terms
of a certain form.
\<close>
definition NO_MATCH :: "'a \<Rightarrow> 'b \<Rightarrow> bool"
where "NO_MATCH pat val \<equiv> True"
lemma NO_MATCH_cong[cong]: "NO_MATCH pat val = NO_MATCH pat val"
by (rule refl)
declare [[coercion_args NO_MATCH - -]]
simproc_setup NO_MATCH ("NO_MATCH pat val") = \<open>fn _ => fn ctxt => fn ct =>
let
val thy = Proof_Context.theory_of ctxt
val dest_binop = Term.dest_comb #> apfst (Term.dest_comb #> snd)
val m = Pattern.matches thy (dest_binop (Thm.term_of ct))
in if m then NONE else SOME @{thm NO_MATCH_def} end
\<close>
text \<open>
This setup ensures that a rewrite rule of the form @{term "NO_MATCH pat val \<Longrightarrow> t"}
is only applied, if the pattern \<open>pat\<close> does not match the value \<open>val\<close>.
\<close>
text\<open>
Tagging a premise of a simp rule with ASSUMPTION forces the simplifier
not to simplify the argument and to solve it by an assumption.
\<close>
definition ASSUMPTION :: "bool \<Rightarrow> bool"
where "ASSUMPTION A \<equiv> A"
lemma ASSUMPTION_cong[cong]: "ASSUMPTION A = ASSUMPTION A"
by (rule refl)
lemma ASSUMPTION_I: "A \<Longrightarrow> ASSUMPTION A"
by (simp add: ASSUMPTION_def)
lemma ASSUMPTION_D: "ASSUMPTION A \<Longrightarrow> A"
by (simp add: ASSUMPTION_def)
setup \<open>
let
val asm_sol = mk_solver "ASSUMPTION" (fn ctxt =>
resolve_tac ctxt [@{thm ASSUMPTION_I}] THEN'
resolve_tac ctxt (Simplifier.prems_of ctxt))
in
map_theory_simpset (fn ctxt => Simplifier.addSolver (ctxt,asm_sol))
end
\<close>
subsection \<open>Code generator setup\<close>
subsubsection \<open>Generic code generator preprocessor setup\<close>
lemma conj_left_cong: "P \<longleftrightarrow> Q \<Longrightarrow> P \<and> R \<longleftrightarrow> Q \<and> R"
by (fact arg_cong)
lemma disj_left_cong: "P \<longleftrightarrow> Q \<Longrightarrow> P \<or> R \<longleftrightarrow> Q \<or> R"
by (fact arg_cong)
setup \<open>
Code_Preproc.map_pre (put_simpset HOL_basic_ss) #>
Code_Preproc.map_post (put_simpset HOL_basic_ss) #>
Code_Simp.map_ss (put_simpset HOL_basic_ss #>
Simplifier.add_cong @{thm conj_left_cong} #>
Simplifier.add_cong @{thm disj_left_cong})
\<close>
subsubsection \<open>Equality\<close>
class equal =
fixes equal :: "'a \<Rightarrow> 'a \<Rightarrow> bool"
assumes equal_eq: "equal x y \<longleftrightarrow> x = y"
begin
lemma equal: "equal = (op =)"
by (rule ext equal_eq)+
lemma equal_refl: "equal x x \<longleftrightarrow> True"
unfolding equal by rule+
lemma eq_equal: "(op =) \<equiv> equal"
by (rule eq_reflection) (rule ext, rule ext, rule sym, rule equal_eq)
end
declare eq_equal [symmetric, code_post]
declare eq_equal [code]
setup \<open>
Code_Preproc.map_pre (fn ctxt =>
ctxt addsimprocs
[Simplifier.make_simproc @{context} "equal"
{lhss = [@{term HOL.eq}],
proc = fn _ => fn _ => fn ct =>
(case Thm.term_of ct of
Const (_, Type (@{type_name fun}, [Type _, _])) => SOME @{thm eq_equal}
| _ => NONE)}])
\<close>
subsubsection \<open>Generic code generator foundation\<close>
text \<open>Datatype @{typ bool}\<close>
code_datatype True False
lemma [code]:
shows "False \<and> P \<longleftrightarrow> False"
and "True \<and> P \<longleftrightarrow> P"
and "P \<and> False \<longleftrightarrow> False"
and "P \<and> True \<longleftrightarrow> P"
by simp_all
lemma [code]:
shows "False \<or> P \<longleftrightarrow> P"
and "True \<or> P \<longleftrightarrow> True"
and "P \<or> False \<longleftrightarrow> P"
and "P \<or> True \<longleftrightarrow> True"
by simp_all
lemma [code]:
shows "(False \<longrightarrow> P) \<longleftrightarrow> True"
and "(True \<longrightarrow> P) \<longleftrightarrow> P"
and "(P \<longrightarrow> False) \<longleftrightarrow> \<not> P"
and "(P \<longrightarrow> True) \<longleftrightarrow> True"
by simp_all
text \<open>More about @{typ prop}\<close>
lemma [code nbe]:
shows "(True \<Longrightarrow> PROP Q) \<equiv> PROP Q"
and "(PROP Q \<Longrightarrow> True) \<equiv> Trueprop True"
and "(P \<Longrightarrow> R) \<equiv> Trueprop (P \<longrightarrow> R)"
by (auto intro!: equal_intr_rule)
lemma Trueprop_code [code]: "Trueprop True \<equiv> Code_Generator.holds"
by (auto intro!: equal_intr_rule holds)
declare Trueprop_code [symmetric, code_post]
text \<open>Equality\<close>
declare simp_thms(6) [code nbe]
instantiation itself :: (type) equal
begin
definition equal_itself :: "'a itself \<Rightarrow> 'a itself \<Rightarrow> bool"
where "equal_itself x y \<longleftrightarrow> x = y"
instance
by standard (fact equal_itself_def)
end
lemma equal_itself_code [code]: "equal TYPE('a) TYPE('a) \<longleftrightarrow> True"
by (simp add: equal)
setup \<open>Sign.add_const_constraint (@{const_name equal}, SOME @{typ "'a::type \<Rightarrow> 'a \<Rightarrow> bool"})\<close>
lemma equal_alias_cert: "OFCLASS('a, equal_class) \<equiv> ((op = :: 'a \<Rightarrow> 'a \<Rightarrow> bool) \<equiv> equal)"
(is "?ofclass \<equiv> ?equal")
proof
assume "PROP ?ofclass"
show "PROP ?equal"
by (tactic \<open>ALLGOALS (resolve_tac @{context} [Thm.unconstrainT @{thm eq_equal}])\<close>)
(fact \<open>PROP ?ofclass\<close>)
next
assume "PROP ?equal"
show "PROP ?ofclass" proof
qed (simp add: \<open>PROP ?equal\<close>)
qed
setup \<open>Sign.add_const_constraint (@{const_name equal}, SOME @{typ "'a::equal \<Rightarrow> 'a \<Rightarrow> bool"})\<close>
setup \<open>Nbe.add_const_alias @{thm equal_alias_cert}\<close>
text \<open>Cases\<close>
lemma Let_case_cert:
assumes "CASE \<equiv> (\<lambda>x. Let x f)"
shows "CASE x \<equiv> f x"
using assms by simp_all
setup \<open>
Code.declare_case_global @{thm Let_case_cert} #>
Code.declare_undefined_global @{const_name undefined}
\<close>
declare [[code abort: undefined]]
subsubsection \<open>Generic code generator target languages\<close>
text \<open>type @{typ bool}\<close>
code_printing
type_constructor bool \<rightharpoonup>
(SML) "bool" and (OCaml) "bool" and (Haskell) "Bool" and (Scala) "Boolean"
| constant True \<rightharpoonup>
(SML) "true" and (OCaml) "true" and (Haskell) "True" and (Scala) "true"
| constant False \<rightharpoonup>
(SML) "false" and (OCaml) "false" and (Haskell) "False" and (Scala) "false"
code_reserved SML
bool true false
code_reserved OCaml
bool
code_reserved Scala
Boolean
code_printing
constant Not \<rightharpoonup>
(SML) "not" and (OCaml) "not" and (Haskell) "not" and (Scala) "'! _"
| constant HOL.conj \<rightharpoonup>
(SML) infixl 1 "andalso" and (OCaml) infixl 3 "&&" and (Haskell) infixr 3 "&&" and (Scala) infixl 3 "&&"
| constant HOL.disj \<rightharpoonup>
(SML) infixl 0 "orelse" and (OCaml) infixl 2 "||" and (Haskell) infixl 2 "||" and (Scala) infixl 1 "||"
| constant HOL.implies \<rightharpoonup>
(SML) "!(if (_)/ then (_)/ else true)"
and (OCaml) "!(if (_)/ then (_)/ else true)"
and (Haskell) "!(if (_)/ then (_)/ else True)"
and (Scala) "!(if ((_))/ (_)/ else true)"
| constant If \<rightharpoonup>
(SML) "!(if (_)/ then (_)/ else (_))"
and (OCaml) "!(if (_)/ then (_)/ else (_))"
and (Haskell) "!(if (_)/ then (_)/ else (_))"
and (Scala) "!(if ((_))/ (_)/ else (_))"
code_reserved SML
not
code_reserved OCaml
not
code_identifier
code_module Pure \<rightharpoonup>
(SML) HOL and (OCaml) HOL and (Haskell) HOL and (Scala) HOL
text \<open>Using built-in Haskell equality.\<close>
code_printing
type_class equal \<rightharpoonup> (Haskell) "Eq"
| constant HOL.equal \<rightharpoonup> (Haskell) infix 4 "=="
| constant HOL.eq \<rightharpoonup> (Haskell) infix 4 "=="
text \<open>\<open>undefined\<close>\<close>
code_printing
constant undefined \<rightharpoonup>
(SML) "!(raise/ Fail/ \"undefined\")"
and (OCaml) "failwith/ \"undefined\""
and (Haskell) "error/ \"undefined\""
and (Scala) "!sys.error(\"undefined\")"
subsubsection \<open>Evaluation and normalization by evaluation\<close>
method_setup eval = \<open>
let
fun eval_tac ctxt =
let val conv = Code_Runtime.dynamic_holds_conv ctxt
in
CONVERSION (Conv.params_conv ~1 (K (Conv.concl_conv ~1 conv)) ctxt) THEN'
resolve_tac ctxt [TrueI]
end
in
Scan.succeed (SIMPLE_METHOD' o eval_tac)
end
\<close> "solve goal by evaluation"
method_setup normalization = \<open>
Scan.succeed (fn ctxt =>
SIMPLE_METHOD'
(CHANGED_PROP o
(CONVERSION (Nbe.dynamic_conv ctxt)
THEN_ALL_NEW (TRY o resolve_tac ctxt [TrueI]))))
\<close> "solve goal by normalization"
subsection \<open>Counterexample Search Units\<close>
subsubsection \<open>Quickcheck\<close>
quickcheck_params [size = 5, iterations = 50]
subsubsection \<open>Nitpick setup\<close>
named_theorems nitpick_unfold "alternative definitions of constants as needed by Nitpick"
and nitpick_simp "equational specification of constants as needed by Nitpick"
and nitpick_psimp "partial equational specification of constants as needed by Nitpick"
and nitpick_choice_spec "choice specification of constants as needed by Nitpick"
declare if_bool_eq_conj [nitpick_unfold, no_atp]
and if_bool_eq_disj [no_atp]
subsection \<open>Preprocessing for the predicate compiler\<close>
named_theorems code_pred_def "alternative definitions of constants for the Predicate Compiler"
and code_pred_inline "inlining definitions for the Predicate Compiler"
and code_pred_simp "simplification rules for the optimisations in the Predicate Compiler"
subsection \<open>Legacy tactics and ML bindings\<close>
ML \<open>
(* combination of (spec RS spec RS ...(j times) ... spec RS mp) *)
local
fun wrong_prem (Const (@{const_name All}, _) $ Abs (_, _, t)) = wrong_prem t
| wrong_prem (Bound _) = true
| wrong_prem _ = false;
val filter_right = filter (not o wrong_prem o HOLogic.dest_Trueprop o hd o Thm.prems_of);
fun smp i = funpow i (fn m => filter_right ([spec] RL m)) [mp];
in
fun smp_tac ctxt j = EVERY' [dresolve_tac ctxt (smp j), assume_tac ctxt];
end;
local
val nnf_ss =
simpset_of (put_simpset HOL_basic_ss @{context} addsimps @{thms simp_thms nnf_simps});
in
fun nnf_conv ctxt = Simplifier.rewrite (put_simpset nnf_ss ctxt);
end
\<close>
hide_const (open) eq equal
end