src/HOL/Set_Interval.thy
author hoelzl
Mon Mar 31 12:16:35 2014 +0200 (2014-03-31)
changeset 56328 b3551501424e
parent 56238 5d147e1e18d1
child 56480 093ea91498e6
permissions -rw-r--r--
add rules about infinity of intervals
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(*  Title:      HOL/Set_Interval.thy
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    Author:     Tobias Nipkow
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    Author:     Clemens Ballarin
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    Author:     Jeremy Avigad
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lessThan, greaterThan, atLeast, atMost and two-sided intervals
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Modern convention: Ixy stands for an interval where x and y
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describe the lower and upper bound and x,y : {c,o,i}
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where c = closed, o = open, i = infinite.
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Examples: Ico = {_ ..< _} and Ici = {_ ..}
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*)
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header {* Set intervals *}
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theory Set_Interval
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imports Lattices_Big Nat_Transfer
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begin
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context ord
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begin
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definition
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  lessThan    :: "'a => 'a set" ("(1{..<_})") where
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  "{..<u} == {x. x < u}"
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definition
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  atMost      :: "'a => 'a set" ("(1{.._})") where
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  "{..u} == {x. x \<le> u}"
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definition
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  greaterThan :: "'a => 'a set" ("(1{_<..})") where
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  "{l<..} == {x. l<x}"
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definition
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  atLeast     :: "'a => 'a set" ("(1{_..})") where
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  "{l..} == {x. l\<le>x}"
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definition
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  greaterThanLessThan :: "'a => 'a => 'a set"  ("(1{_<..<_})") where
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  "{l<..<u} == {l<..} Int {..<u}"
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definition
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  atLeastLessThan :: "'a => 'a => 'a set"      ("(1{_..<_})") where
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  "{l..<u} == {l..} Int {..<u}"
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definition
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  greaterThanAtMost :: "'a => 'a => 'a set"    ("(1{_<.._})") where
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  "{l<..u} == {l<..} Int {..u}"
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definition
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  atLeastAtMost :: "'a => 'a => 'a set"        ("(1{_.._})") where
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  "{l..u} == {l..} Int {..u}"
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end
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text{* A note of warning when using @{term"{..<n}"} on type @{typ
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nat}: it is equivalent to @{term"{0::nat..<n}"} but some lemmas involving
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@{term"{m..<n}"} may not exist in @{term"{..<n}"}-form as well. *}
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syntax
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  "_UNION_le"   :: "'a => 'a => 'b set => 'b set"       ("(3UN _<=_./ _)" [0, 0, 10] 10)
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  "_UNION_less" :: "'a => 'a => 'b set => 'b set"       ("(3UN _<_./ _)" [0, 0, 10] 10)
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  "_INTER_le"   :: "'a => 'a => 'b set => 'b set"       ("(3INT _<=_./ _)" [0, 0, 10] 10)
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  "_INTER_less" :: "'a => 'a => 'b set => 'b set"       ("(3INT _<_./ _)" [0, 0, 10] 10)
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syntax (xsymbols)
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  "_UNION_le"   :: "'a => 'a => 'b set => 'b set"       ("(3\<Union> _\<le>_./ _)" [0, 0, 10] 10)
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  "_UNION_less" :: "'a => 'a => 'b set => 'b set"       ("(3\<Union> _<_./ _)" [0, 0, 10] 10)
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  "_INTER_le"   :: "'a => 'a => 'b set => 'b set"       ("(3\<Inter> _\<le>_./ _)" [0, 0, 10] 10)
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  "_INTER_less" :: "'a => 'a => 'b set => 'b set"       ("(3\<Inter> _<_./ _)" [0, 0, 10] 10)
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syntax (latex output)
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  "_UNION_le"   :: "'a \<Rightarrow> 'a => 'b set => 'b set"       ("(3\<Union>(00_ \<le> _)/ _)" [0, 0, 10] 10)
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  "_UNION_less" :: "'a \<Rightarrow> 'a => 'b set => 'b set"       ("(3\<Union>(00_ < _)/ _)" [0, 0, 10] 10)
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  "_INTER_le"   :: "'a \<Rightarrow> 'a => 'b set => 'b set"       ("(3\<Inter>(00_ \<le> _)/ _)" [0, 0, 10] 10)
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  "_INTER_less" :: "'a \<Rightarrow> 'a => 'b set => 'b set"       ("(3\<Inter>(00_ < _)/ _)" [0, 0, 10] 10)
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translations
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  "UN i<=n. A"  == "UN i:{..n}. A"
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  "UN i<n. A"   == "UN i:{..<n}. A"
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  "INT i<=n. A" == "INT i:{..n}. A"
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  "INT i<n. A"  == "INT i:{..<n}. A"
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subsection {* Various equivalences *}
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lemma (in ord) lessThan_iff [iff]: "(i: lessThan k) = (i<k)"
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by (simp add: lessThan_def)
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lemma Compl_lessThan [simp]:
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    "!!k:: 'a::linorder. -lessThan k = atLeast k"
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apply (auto simp add: lessThan_def atLeast_def)
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done
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lemma single_Diff_lessThan [simp]: "!!k:: 'a::order. {k} - lessThan k = {k}"
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by auto
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lemma (in ord) greaterThan_iff [iff]: "(i: greaterThan k) = (k<i)"
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by (simp add: greaterThan_def)
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lemma Compl_greaterThan [simp]:
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    "!!k:: 'a::linorder. -greaterThan k = atMost k"
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  by (auto simp add: greaterThan_def atMost_def)
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lemma Compl_atMost [simp]: "!!k:: 'a::linorder. -atMost k = greaterThan k"
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apply (subst Compl_greaterThan [symmetric])
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apply (rule double_complement)
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done
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lemma (in ord) atLeast_iff [iff]: "(i: atLeast k) = (k<=i)"
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by (simp add: atLeast_def)
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lemma Compl_atLeast [simp]:
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    "!!k:: 'a::linorder. -atLeast k = lessThan k"
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  by (auto simp add: lessThan_def atLeast_def)
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lemma (in ord) atMost_iff [iff]: "(i: atMost k) = (i<=k)"
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by (simp add: atMost_def)
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lemma atMost_Int_atLeast: "!!n:: 'a::order. atMost n Int atLeast n = {n}"
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by (blast intro: order_antisym)
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lemma (in linorder) lessThan_Int_lessThan: "{ a <..} \<inter> { b <..} = { max a b <..}"
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  by auto
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lemma (in linorder) greaterThan_Int_greaterThan: "{..< a} \<inter> {..< b} = {..< min a b}"
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  by auto
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subsection {* Logical Equivalences for Set Inclusion and Equality *}
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lemma atLeast_subset_iff [iff]:
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     "(atLeast x \<subseteq> atLeast y) = (y \<le> (x::'a::order))"
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by (blast intro: order_trans)
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lemma atLeast_eq_iff [iff]:
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     "(atLeast x = atLeast y) = (x = (y::'a::linorder))"
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by (blast intro: order_antisym order_trans)
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lemma greaterThan_subset_iff [iff]:
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     "(greaterThan x \<subseteq> greaterThan y) = (y \<le> (x::'a::linorder))"
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apply (auto simp add: greaterThan_def)
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 apply (subst linorder_not_less [symmetric], blast)
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done
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lemma greaterThan_eq_iff [iff]:
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     "(greaterThan x = greaterThan y) = (x = (y::'a::linorder))"
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apply (rule iffI)
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 apply (erule equalityE)
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 apply simp_all
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done
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lemma atMost_subset_iff [iff]: "(atMost x \<subseteq> atMost y) = (x \<le> (y::'a::order))"
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by (blast intro: order_trans)
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lemma atMost_eq_iff [iff]: "(atMost x = atMost y) = (x = (y::'a::linorder))"
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by (blast intro: order_antisym order_trans)
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lemma lessThan_subset_iff [iff]:
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     "(lessThan x \<subseteq> lessThan y) = (x \<le> (y::'a::linorder))"
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apply (auto simp add: lessThan_def)
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 apply (subst linorder_not_less [symmetric], blast)
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done
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lemma lessThan_eq_iff [iff]:
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     "(lessThan x = lessThan y) = (x = (y::'a::linorder))"
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apply (rule iffI)
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 apply (erule equalityE)
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 apply simp_all
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done
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lemma lessThan_strict_subset_iff:
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  fixes m n :: "'a::linorder"
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  shows "{..<m} < {..<n} \<longleftrightarrow> m < n"
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  by (metis leD lessThan_subset_iff linorder_linear not_less_iff_gr_or_eq psubset_eq)
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subsection {*Two-sided intervals*}
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context ord
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begin
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lemma greaterThanLessThan_iff [simp]:
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  "(i : {l<..<u}) = (l < i & i < u)"
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by (simp add: greaterThanLessThan_def)
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lemma atLeastLessThan_iff [simp]:
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  "(i : {l..<u}) = (l <= i & i < u)"
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by (simp add: atLeastLessThan_def)
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lemma greaterThanAtMost_iff [simp]:
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  "(i : {l<..u}) = (l < i & i <= u)"
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by (simp add: greaterThanAtMost_def)
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lemma atLeastAtMost_iff [simp]:
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  "(i : {l..u}) = (l <= i & i <= u)"
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by (simp add: atLeastAtMost_def)
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text {* The above four lemmas could be declared as iffs. Unfortunately this
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breaks many proofs. Since it only helps blast, it is better to leave them
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alone. *}
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lemma greaterThanLessThan_eq: "{ a <..< b} = { a <..} \<inter> {..< b }"
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  by auto
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end
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subsubsection{* Emptyness, singletons, subset *}
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context order
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begin
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lemma atLeastatMost_empty[simp]:
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  "b < a \<Longrightarrow> {a..b} = {}"
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by(auto simp: atLeastAtMost_def atLeast_def atMost_def)
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lemma atLeastatMost_empty_iff[simp]:
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  "{a..b} = {} \<longleftrightarrow> (~ a <= b)"
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by auto (blast intro: order_trans)
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lemma atLeastatMost_empty_iff2[simp]:
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  "{} = {a..b} \<longleftrightarrow> (~ a <= b)"
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by auto (blast intro: order_trans)
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lemma atLeastLessThan_empty[simp]:
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  "b <= a \<Longrightarrow> {a..<b} = {}"
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by(auto simp: atLeastLessThan_def)
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lemma atLeastLessThan_empty_iff[simp]:
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  "{a..<b} = {} \<longleftrightarrow> (~ a < b)"
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by auto (blast intro: le_less_trans)
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lemma atLeastLessThan_empty_iff2[simp]:
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  "{} = {a..<b} \<longleftrightarrow> (~ a < b)"
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by auto (blast intro: le_less_trans)
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lemma greaterThanAtMost_empty[simp]: "l \<le> k ==> {k<..l} = {}"
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by(auto simp:greaterThanAtMost_def greaterThan_def atMost_def)
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lemma greaterThanAtMost_empty_iff[simp]: "{k<..l} = {} \<longleftrightarrow> ~ k < l"
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by auto (blast intro: less_le_trans)
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lemma greaterThanAtMost_empty_iff2[simp]: "{} = {k<..l} \<longleftrightarrow> ~ k < l"
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by auto (blast intro: less_le_trans)
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lemma greaterThanLessThan_empty[simp]:"l \<le> k ==> {k<..<l} = {}"
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by(auto simp:greaterThanLessThan_def greaterThan_def lessThan_def)
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lemma atLeastAtMost_singleton [simp]: "{a..a} = {a}"
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by (auto simp add: atLeastAtMost_def atMost_def atLeast_def)
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lemma atLeastAtMost_singleton': "a = b \<Longrightarrow> {a .. b} = {a}" by simp
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lemma atLeastatMost_subset_iff[simp]:
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  "{a..b} <= {c..d} \<longleftrightarrow> (~ a <= b) | c <= a & b <= d"
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unfolding atLeastAtMost_def atLeast_def atMost_def
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by (blast intro: order_trans)
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lemma atLeastatMost_psubset_iff:
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  "{a..b} < {c..d} \<longleftrightarrow>
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   ((~ a <= b) | c <= a & b <= d & (c < a | b < d))  &  c <= d"
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by(simp add: psubset_eq set_eq_iff less_le_not_le)(blast intro: order_trans)
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lemma Icc_eq_Icc[simp]:
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  "{l..h} = {l'..h'} = (l=l' \<and> h=h' \<or> \<not> l\<le>h \<and> \<not> l'\<le>h')"
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by(simp add: order_class.eq_iff)(auto intro: order_trans)
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lemma atLeastAtMost_singleton_iff[simp]:
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  "{a .. b} = {c} \<longleftrightarrow> a = b \<and> b = c"
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proof
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  assume "{a..b} = {c}"
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  hence *: "\<not> (\<not> a \<le> b)" unfolding atLeastatMost_empty_iff[symmetric] by simp
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  with `{a..b} = {c}` have "c \<le> a \<and> b \<le> c" by auto
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  with * show "a = b \<and> b = c" by auto
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qed simp
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lemma Icc_subset_Ici_iff[simp]:
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  "{l..h} \<subseteq> {l'..} = (~ l\<le>h \<or> l\<ge>l')"
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by(auto simp: subset_eq intro: order_trans)
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lemma Icc_subset_Iic_iff[simp]:
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  "{l..h} \<subseteq> {..h'} = (~ l\<le>h \<or> h\<le>h')"
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by(auto simp: subset_eq intro: order_trans)
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lemma not_Ici_eq_empty[simp]: "{l..} \<noteq> {}"
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by(auto simp: set_eq_iff)
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lemma not_Iic_eq_empty[simp]: "{..h} \<noteq> {}"
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by(auto simp: set_eq_iff)
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lemmas not_empty_eq_Ici_eq_empty[simp] = not_Ici_eq_empty[symmetric]
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lemmas not_empty_eq_Iic_eq_empty[simp] = not_Iic_eq_empty[symmetric]
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end
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context no_top
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begin
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(* also holds for no_bot but no_top should suffice *)
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lemma not_UNIV_le_Icc[simp]: "\<not> UNIV \<subseteq> {l..h}"
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using gt_ex[of h] by(auto simp: subset_eq less_le_not_le)
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lemma not_UNIV_le_Iic[simp]: "\<not> UNIV \<subseteq> {..h}"
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using gt_ex[of h] by(auto simp: subset_eq less_le_not_le)
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lemma not_Ici_le_Icc[simp]: "\<not> {l..} \<subseteq> {l'..h'}"
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using gt_ex[of h']
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by(auto simp: subset_eq less_le)(blast dest:antisym_conv intro: order_trans)
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lemma not_Ici_le_Iic[simp]: "\<not> {l..} \<subseteq> {..h'}"
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using gt_ex[of h']
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by(auto simp: subset_eq less_le)(blast dest:antisym_conv intro: order_trans)
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end
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context no_bot
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begin
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lemma not_UNIV_le_Ici[simp]: "\<not> UNIV \<subseteq> {l..}"
nipkow@51334
   320
using lt_ex[of l] by(auto simp: subset_eq less_le_not_le)
nipkow@51334
   321
nipkow@51334
   322
lemma not_Iic_le_Icc[simp]: "\<not> {..h} \<subseteq> {l'..h'}"
nipkow@51334
   323
using lt_ex[of l']
nipkow@51334
   324
by(auto simp: subset_eq less_le)(blast dest:antisym_conv intro: order_trans)
nipkow@51334
   325
nipkow@51334
   326
lemma not_Iic_le_Ici[simp]: "\<not> {..h} \<subseteq> {l'..}"
nipkow@51334
   327
using lt_ex[of l']
nipkow@51334
   328
by(auto simp: subset_eq less_le)(blast dest:antisym_conv intro: order_trans)
nipkow@51334
   329
nipkow@51334
   330
end
nipkow@51334
   331
nipkow@51334
   332
nipkow@51334
   333
context no_top
nipkow@51334
   334
begin
nipkow@51334
   335
nipkow@51334
   336
(* also holds for no_bot but no_top should suffice *)
nipkow@51334
   337
lemma not_UNIV_eq_Icc[simp]: "\<not> UNIV = {l'..h'}"
nipkow@51334
   338
using gt_ex[of h'] by(auto simp: set_eq_iff  less_le_not_le)
nipkow@51334
   339
nipkow@51334
   340
lemmas not_Icc_eq_UNIV[simp] = not_UNIV_eq_Icc[symmetric]
nipkow@51334
   341
nipkow@51334
   342
lemma not_UNIV_eq_Iic[simp]: "\<not> UNIV = {..h'}"
nipkow@51334
   343
using gt_ex[of h'] by(auto simp: set_eq_iff  less_le_not_le)
nipkow@51334
   344
nipkow@51334
   345
lemmas not_Iic_eq_UNIV[simp] = not_UNIV_eq_Iic[symmetric]
nipkow@51334
   346
nipkow@51334
   347
lemma not_Icc_eq_Ici[simp]: "\<not> {l..h} = {l'..}"
nipkow@51334
   348
unfolding atLeastAtMost_def using not_Ici_le_Iic[of l'] by blast
nipkow@51334
   349
nipkow@51334
   350
lemmas not_Ici_eq_Icc[simp] = not_Icc_eq_Ici[symmetric]
nipkow@51334
   351
nipkow@51334
   352
(* also holds for no_bot but no_top should suffice *)
nipkow@51334
   353
lemma not_Iic_eq_Ici[simp]: "\<not> {..h} = {l'..}"
nipkow@51334
   354
using not_Ici_le_Iic[of l' h] by blast
nipkow@51334
   355
nipkow@51334
   356
lemmas not_Ici_eq_Iic[simp] = not_Iic_eq_Ici[symmetric]
nipkow@51334
   357
nipkow@51334
   358
end
nipkow@51334
   359
nipkow@51334
   360
context no_bot
nipkow@51334
   361
begin
nipkow@51334
   362
nipkow@51334
   363
lemma not_UNIV_eq_Ici[simp]: "\<not> UNIV = {l'..}"
nipkow@51334
   364
using lt_ex[of l'] by(auto simp: set_eq_iff  less_le_not_le)
nipkow@51334
   365
nipkow@51334
   366
lemmas not_Ici_eq_UNIV[simp] = not_UNIV_eq_Ici[symmetric]
nipkow@51334
   367
nipkow@51334
   368
lemma not_Icc_eq_Iic[simp]: "\<not> {l..h} = {..h'}"
nipkow@51334
   369
unfolding atLeastAtMost_def using not_Iic_le_Ici[of h'] by blast
nipkow@51334
   370
nipkow@51334
   371
lemmas not_Iic_eq_Icc[simp] = not_Icc_eq_Iic[symmetric]
nipkow@51334
   372
nipkow@51334
   373
end
nipkow@51334
   374
nipkow@51334
   375
hoelzl@53216
   376
context dense_linorder
hoelzl@42891
   377
begin
hoelzl@42891
   378
hoelzl@42891
   379
lemma greaterThanLessThan_empty_iff[simp]:
hoelzl@42891
   380
  "{ a <..< b } = {} \<longleftrightarrow> b \<le> a"
hoelzl@42891
   381
  using dense[of a b] by (cases "a < b") auto
hoelzl@42891
   382
hoelzl@42891
   383
lemma greaterThanLessThan_empty_iff2[simp]:
hoelzl@42891
   384
  "{} = { a <..< b } \<longleftrightarrow> b \<le> a"
hoelzl@42891
   385
  using dense[of a b] by (cases "a < b") auto
hoelzl@42891
   386
hoelzl@42901
   387
lemma atLeastLessThan_subseteq_atLeastAtMost_iff:
hoelzl@42901
   388
  "{a ..< b} \<subseteq> { c .. d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b \<le> d)"
hoelzl@42901
   389
  using dense[of "max a d" "b"]
hoelzl@42901
   390
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@42901
   391
hoelzl@42901
   392
lemma greaterThanAtMost_subseteq_atLeastAtMost_iff:
hoelzl@42901
   393
  "{a <.. b} \<subseteq> { c .. d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b \<le> d)"
hoelzl@42901
   394
  using dense[of "a" "min c b"]
hoelzl@42901
   395
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@42901
   396
hoelzl@42901
   397
lemma greaterThanLessThan_subseteq_atLeastAtMost_iff:
hoelzl@42901
   398
  "{a <..< b} \<subseteq> { c .. d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b \<le> d)"
hoelzl@42901
   399
  using dense[of "a" "min c b"] dense[of "max a d" "b"]
hoelzl@42901
   400
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@42901
   401
hoelzl@43657
   402
lemma atLeastAtMost_subseteq_atLeastLessThan_iff:
hoelzl@43657
   403
  "{a .. b} \<subseteq> { c ..< d } \<longleftrightarrow> (a \<le> b \<longrightarrow> c \<le> a \<and> b < d)"
hoelzl@43657
   404
  using dense[of "max a d" "b"]
hoelzl@43657
   405
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@43657
   406
hoelzl@43657
   407
lemma greaterThanAtMost_subseteq_atLeastLessThan_iff:
hoelzl@43657
   408
  "{a <.. b} \<subseteq> { c ..< d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b < d)"
hoelzl@43657
   409
  using dense[of "a" "min c b"]
hoelzl@43657
   410
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@43657
   411
hoelzl@43657
   412
lemma greaterThanLessThan_subseteq_atLeastLessThan_iff:
hoelzl@43657
   413
  "{a <..< b} \<subseteq> { c ..< d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b \<le> d)"
hoelzl@43657
   414
  using dense[of "a" "min c b"] dense[of "max a d" "b"]
hoelzl@43657
   415
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@43657
   416
hoelzl@56328
   417
lemma greaterThanLessThan_subseteq_greaterThanAtMost_iff:
hoelzl@56328
   418
  "{a <..< b} \<subseteq> { c <.. d } \<longleftrightarrow> (a < b \<longrightarrow> c \<le> a \<and> b \<le> d)"
hoelzl@56328
   419
  using dense[of "a" "min c b"] dense[of "max a d" "b"]
hoelzl@56328
   420
  by (force simp: subset_eq Ball_def not_less[symmetric])
hoelzl@56328
   421
hoelzl@42891
   422
end
hoelzl@42891
   423
hoelzl@51329
   424
context no_top
hoelzl@51329
   425
begin
hoelzl@51329
   426
nipkow@51334
   427
lemma greaterThan_non_empty[simp]: "{x <..} \<noteq> {}"
hoelzl@51329
   428
  using gt_ex[of x] by auto
hoelzl@51329
   429
hoelzl@51329
   430
end
hoelzl@51329
   431
hoelzl@51329
   432
context no_bot
hoelzl@51329
   433
begin
hoelzl@51329
   434
nipkow@51334
   435
lemma lessThan_non_empty[simp]: "{..< x} \<noteq> {}"
hoelzl@51329
   436
  using lt_ex[of x] by auto
hoelzl@51329
   437
hoelzl@51329
   438
end
hoelzl@51329
   439
nipkow@32408
   440
lemma (in linorder) atLeastLessThan_subset_iff:
nipkow@32408
   441
  "{a..<b} <= {c..<d} \<Longrightarrow> b <= a | c<=a & b<=d"
nipkow@32408
   442
apply (auto simp:subset_eq Ball_def)
nipkow@32408
   443
apply(frule_tac x=a in spec)
nipkow@32408
   444
apply(erule_tac x=d in allE)
nipkow@32408
   445
apply (simp add: less_imp_le)
nipkow@32408
   446
done
nipkow@32408
   447
hoelzl@40703
   448
lemma atLeastLessThan_inj:
hoelzl@40703
   449
  fixes a b c d :: "'a::linorder"
hoelzl@40703
   450
  assumes eq: "{a ..< b} = {c ..< d}" and "a < b" "c < d"
hoelzl@40703
   451
  shows "a = c" "b = d"
hoelzl@40703
   452
using assms by (metis atLeastLessThan_subset_iff eq less_le_not_le linorder_antisym_conv2 subset_refl)+
hoelzl@40703
   453
hoelzl@40703
   454
lemma atLeastLessThan_eq_iff:
hoelzl@40703
   455
  fixes a b c d :: "'a::linorder"
hoelzl@40703
   456
  assumes "a < b" "c < d"
hoelzl@40703
   457
  shows "{a ..< b} = {c ..< d} \<longleftrightarrow> a = c \<and> b = d"
hoelzl@40703
   458
  using atLeastLessThan_inj assms by auto
hoelzl@40703
   459
haftmann@52729
   460
lemma (in order_bot) atLeast_eq_UNIV_iff: "{x..} = UNIV \<longleftrightarrow> x = bot"
nipkow@51334
   461
by (auto simp: set_eq_iff intro: le_bot)
hoelzl@51328
   462
haftmann@52729
   463
lemma (in order_top) atMost_eq_UNIV_iff: "{..x} = UNIV \<longleftrightarrow> x = top"
nipkow@51334
   464
by (auto simp: set_eq_iff intro: top_le)
hoelzl@51328
   465
nipkow@51334
   466
lemma (in bounded_lattice) atLeastAtMost_eq_UNIV_iff:
nipkow@51334
   467
  "{x..y} = UNIV \<longleftrightarrow> (x = bot \<and> y = top)"
nipkow@51334
   468
by (auto simp: set_eq_iff intro: top_le le_bot)
hoelzl@51328
   469
hoelzl@51328
   470
hoelzl@56328
   471
subsection {* Infinite intervals *}
hoelzl@56328
   472
hoelzl@56328
   473
context dense_linorder
hoelzl@56328
   474
begin
hoelzl@56328
   475
hoelzl@56328
   476
lemma infinite_Ioo:
hoelzl@56328
   477
  assumes "a < b"
hoelzl@56328
   478
  shows "\<not> finite {a<..<b}"
hoelzl@56328
   479
proof
hoelzl@56328
   480
  assume fin: "finite {a<..<b}"
hoelzl@56328
   481
  moreover have ne: "{a<..<b} \<noteq> {}"
hoelzl@56328
   482
    using `a < b` by auto
hoelzl@56328
   483
  ultimately have "a < Max {a <..< b}" "Max {a <..< b} < b"
hoelzl@56328
   484
    using Max_in[of "{a <..< b}"] by auto
hoelzl@56328
   485
  then obtain x where "Max {a <..< b} < x" "x < b"
hoelzl@56328
   486
    using dense[of "Max {a<..<b}" b] by auto
hoelzl@56328
   487
  then have "x \<in> {a <..< b}"
hoelzl@56328
   488
    using `a < Max {a <..< b}` by auto
hoelzl@56328
   489
  then have "x \<le> Max {a <..< b}"
hoelzl@56328
   490
    using fin by auto
hoelzl@56328
   491
  with `Max {a <..< b} < x` show False by auto
hoelzl@56328
   492
qed
hoelzl@56328
   493
hoelzl@56328
   494
lemma infinite_Icc: "a < b \<Longrightarrow> \<not> finite {a .. b}"
hoelzl@56328
   495
  using greaterThanLessThan_subseteq_atLeastAtMost_iff[of a b a b] infinite_Ioo[of a b]
hoelzl@56328
   496
  by (auto dest: finite_subset)
hoelzl@56328
   497
hoelzl@56328
   498
lemma infinite_Ico: "a < b \<Longrightarrow> \<not> finite {a ..< b}"
hoelzl@56328
   499
  using greaterThanLessThan_subseteq_atLeastLessThan_iff[of a b a b] infinite_Ioo[of a b]
hoelzl@56328
   500
  by (auto dest: finite_subset)
hoelzl@56328
   501
hoelzl@56328
   502
lemma infinite_Ioc: "a < b \<Longrightarrow> \<not> finite {a <.. b}"
hoelzl@56328
   503
  using greaterThanLessThan_subseteq_greaterThanAtMost_iff[of a b a b] infinite_Ioo[of a b]
hoelzl@56328
   504
  by (auto dest: finite_subset)
hoelzl@56328
   505
hoelzl@56328
   506
end
hoelzl@56328
   507
hoelzl@56328
   508
lemma infinite_Iio: "\<not> finite {..< a :: 'a :: {no_bot, linorder}}"
hoelzl@56328
   509
proof
hoelzl@56328
   510
  assume "finite {..< a}"
hoelzl@56328
   511
  then have *: "\<And>x. x < a \<Longrightarrow> Min {..< a} \<le> x"
hoelzl@56328
   512
    by auto
hoelzl@56328
   513
  obtain x where "x < a"
hoelzl@56328
   514
    using lt_ex by auto
hoelzl@56328
   515
hoelzl@56328
   516
  obtain y where "y < Min {..< a}"
hoelzl@56328
   517
    using lt_ex by auto
hoelzl@56328
   518
  also have "Min {..< a} \<le> x"
hoelzl@56328
   519
    using `x < a` by fact
hoelzl@56328
   520
  also note `x < a`
hoelzl@56328
   521
  finally have "Min {..< a} \<le> y"
hoelzl@56328
   522
    by fact
hoelzl@56328
   523
  with `y < Min {..< a}` show False by auto
hoelzl@56328
   524
qed
hoelzl@56328
   525
hoelzl@56328
   526
lemma infinite_Iic: "\<not> finite {.. a :: 'a :: {no_bot, linorder}}"
hoelzl@56328
   527
  using infinite_Iio[of a] finite_subset[of "{..< a}" "{.. a}"]
hoelzl@56328
   528
  by (auto simp: subset_eq less_imp_le)
hoelzl@56328
   529
hoelzl@56328
   530
lemma infinite_Ioi: "\<not> finite {a :: 'a :: {no_top, linorder} <..}"
hoelzl@56328
   531
proof
hoelzl@56328
   532
  assume "finite {a <..}"
hoelzl@56328
   533
  then have *: "\<And>x. a < x \<Longrightarrow> x \<le> Max {a <..}"
hoelzl@56328
   534
    by auto
hoelzl@56328
   535
hoelzl@56328
   536
  obtain y where "Max {a <..} < y"
hoelzl@56328
   537
    using gt_ex by auto
hoelzl@56328
   538
hoelzl@56328
   539
  obtain x where "a < x"
hoelzl@56328
   540
    using gt_ex by auto
hoelzl@56328
   541
  also then have "x \<le> Max {a <..}"
hoelzl@56328
   542
    by fact
hoelzl@56328
   543
  also note `Max {a <..} < y`
hoelzl@56328
   544
  finally have "y \<le> Max { a <..}"
hoelzl@56328
   545
    by fact
hoelzl@56328
   546
  with `Max {a <..} < y` show False by auto
hoelzl@56328
   547
qed
hoelzl@56328
   548
hoelzl@56328
   549
lemma infinite_Ici: "\<not> finite {a :: 'a :: {no_top, linorder} ..}"
hoelzl@56328
   550
  using infinite_Ioi[of a] finite_subset[of "{a <..}" "{a ..}"]
hoelzl@56328
   551
  by (auto simp: subset_eq less_imp_le)
hoelzl@56328
   552
nipkow@32456
   553
subsubsection {* Intersection *}
nipkow@32456
   554
nipkow@32456
   555
context linorder
nipkow@32456
   556
begin
nipkow@32456
   557
nipkow@32456
   558
lemma Int_atLeastAtMost[simp]: "{a..b} Int {c..d} = {max a c .. min b d}"
nipkow@32456
   559
by auto
nipkow@32456
   560
nipkow@32456
   561
lemma Int_atLeastAtMostR1[simp]: "{..b} Int {c..d} = {c .. min b d}"
nipkow@32456
   562
by auto
nipkow@32456
   563
nipkow@32456
   564
lemma Int_atLeastAtMostR2[simp]: "{a..} Int {c..d} = {max a c .. d}"
nipkow@32456
   565
by auto
nipkow@32456
   566
nipkow@32456
   567
lemma Int_atLeastAtMostL1[simp]: "{a..b} Int {..d} = {a .. min b d}"
nipkow@32456
   568
by auto
nipkow@32456
   569
nipkow@32456
   570
lemma Int_atLeastAtMostL2[simp]: "{a..b} Int {c..} = {max a c .. b}"
nipkow@32456
   571
by auto
nipkow@32456
   572
nipkow@32456
   573
lemma Int_atLeastLessThan[simp]: "{a..<b} Int {c..<d} = {max a c ..< min b d}"
nipkow@32456
   574
by auto
nipkow@32456
   575
nipkow@32456
   576
lemma Int_greaterThanAtMost[simp]: "{a<..b} Int {c<..d} = {max a c <.. min b d}"
nipkow@32456
   577
by auto
nipkow@32456
   578
nipkow@32456
   579
lemma Int_greaterThanLessThan[simp]: "{a<..<b} Int {c<..<d} = {max a c <..< min b d}"
nipkow@32456
   580
by auto
nipkow@32456
   581
hoelzl@50417
   582
lemma Int_atMost[simp]: "{..a} \<inter> {..b} = {.. min a b}"
hoelzl@50417
   583
  by (auto simp: min_def)
hoelzl@50417
   584
nipkow@32456
   585
end
nipkow@32456
   586
hoelzl@51329
   587
context complete_lattice
hoelzl@51329
   588
begin
hoelzl@51329
   589
hoelzl@51329
   590
lemma
hoelzl@51329
   591
  shows Sup_atLeast[simp]: "Sup {x ..} = top"
hoelzl@51329
   592
    and Sup_greaterThanAtLeast[simp]: "x < top \<Longrightarrow> Sup {x <..} = top"
hoelzl@51329
   593
    and Sup_atMost[simp]: "Sup {.. y} = y"
hoelzl@51329
   594
    and Sup_atLeastAtMost[simp]: "x \<le> y \<Longrightarrow> Sup { x .. y} = y"
hoelzl@51329
   595
    and Sup_greaterThanAtMost[simp]: "x < y \<Longrightarrow> Sup { x <.. y} = y"
hoelzl@51329
   596
  by (auto intro!: Sup_eqI)
hoelzl@51329
   597
hoelzl@51329
   598
lemma
hoelzl@51329
   599
  shows Inf_atMost[simp]: "Inf {.. x} = bot"
hoelzl@51329
   600
    and Inf_atMostLessThan[simp]: "top < x \<Longrightarrow> Inf {..< x} = bot"
hoelzl@51329
   601
    and Inf_atLeast[simp]: "Inf {x ..} = x"
hoelzl@51329
   602
    and Inf_atLeastAtMost[simp]: "x \<le> y \<Longrightarrow> Inf { x .. y} = x"
hoelzl@51329
   603
    and Inf_atLeastLessThan[simp]: "x < y \<Longrightarrow> Inf { x ..< y} = x"
hoelzl@51329
   604
  by (auto intro!: Inf_eqI)
hoelzl@51329
   605
hoelzl@51329
   606
end
hoelzl@51329
   607
hoelzl@51329
   608
lemma
hoelzl@53216
   609
  fixes x y :: "'a :: {complete_lattice, dense_linorder}"
hoelzl@51329
   610
  shows Sup_lessThan[simp]: "Sup {..< y} = y"
hoelzl@51329
   611
    and Sup_atLeastLessThan[simp]: "x < y \<Longrightarrow> Sup { x ..< y} = y"
hoelzl@51329
   612
    and Sup_greaterThanLessThan[simp]: "x < y \<Longrightarrow> Sup { x <..< y} = y"
hoelzl@51329
   613
    and Inf_greaterThan[simp]: "Inf {x <..} = x"
hoelzl@51329
   614
    and Inf_greaterThanAtMost[simp]: "x < y \<Longrightarrow> Inf { x <.. y} = x"
hoelzl@51329
   615
    and Inf_greaterThanLessThan[simp]: "x < y \<Longrightarrow> Inf { x <..< y} = x"
hoelzl@51329
   616
  by (auto intro!: Inf_eqI Sup_eqI intro: dense_le dense_le_bounded dense_ge dense_ge_bounded)
nipkow@32456
   617
paulson@14485
   618
subsection {* Intervals of natural numbers *}
paulson@14485
   619
paulson@15047
   620
subsubsection {* The Constant @{term lessThan} *}
paulson@15047
   621
paulson@14485
   622
lemma lessThan_0 [simp]: "lessThan (0::nat) = {}"
paulson@14485
   623
by (simp add: lessThan_def)
paulson@14485
   624
paulson@14485
   625
lemma lessThan_Suc: "lessThan (Suc k) = insert k (lessThan k)"
paulson@14485
   626
by (simp add: lessThan_def less_Suc_eq, blast)
paulson@14485
   627
kleing@43156
   628
text {* The following proof is convenient in induction proofs where
hoelzl@39072
   629
new elements get indices at the beginning. So it is used to transform
hoelzl@39072
   630
@{term "{..<Suc n}"} to @{term "0::nat"} and @{term "{..< n}"}. *}
hoelzl@39072
   631
hoelzl@39072
   632
lemma lessThan_Suc_eq_insert_0: "{..<Suc n} = insert 0 (Suc ` {..<n})"
hoelzl@39072
   633
proof safe
hoelzl@39072
   634
  fix x assume "x < Suc n" "x \<notin> Suc ` {..<n}"
hoelzl@39072
   635
  then have "x \<noteq> Suc (x - 1)" by auto
hoelzl@39072
   636
  with `x < Suc n` show "x = 0" by auto
hoelzl@39072
   637
qed
hoelzl@39072
   638
paulson@14485
   639
lemma lessThan_Suc_atMost: "lessThan (Suc k) = atMost k"
paulson@14485
   640
by (simp add: lessThan_def atMost_def less_Suc_eq_le)
paulson@14485
   641
paulson@14485
   642
lemma UN_lessThan_UNIV: "(UN m::nat. lessThan m) = UNIV"
paulson@14485
   643
by blast
paulson@14485
   644
paulson@15047
   645
subsubsection {* The Constant @{term greaterThan} *}
paulson@15047
   646
paulson@14485
   647
lemma greaterThan_0 [simp]: "greaterThan 0 = range Suc"
paulson@14485
   648
apply (simp add: greaterThan_def)
paulson@14485
   649
apply (blast dest: gr0_conv_Suc [THEN iffD1])
paulson@14485
   650
done
paulson@14485
   651
paulson@14485
   652
lemma greaterThan_Suc: "greaterThan (Suc k) = greaterThan k - {Suc k}"
paulson@14485
   653
apply (simp add: greaterThan_def)
paulson@14485
   654
apply (auto elim: linorder_neqE)
paulson@14485
   655
done
paulson@14485
   656
paulson@14485
   657
lemma INT_greaterThan_UNIV: "(INT m::nat. greaterThan m) = {}"
paulson@14485
   658
by blast
paulson@14485
   659
paulson@15047
   660
subsubsection {* The Constant @{term atLeast} *}
paulson@15047
   661
paulson@14485
   662
lemma atLeast_0 [simp]: "atLeast (0::nat) = UNIV"
paulson@14485
   663
by (unfold atLeast_def UNIV_def, simp)
paulson@14485
   664
paulson@14485
   665
lemma atLeast_Suc: "atLeast (Suc k) = atLeast k - {k}"
paulson@14485
   666
apply (simp add: atLeast_def)
paulson@14485
   667
apply (simp add: Suc_le_eq)
paulson@14485
   668
apply (simp add: order_le_less, blast)
paulson@14485
   669
done
paulson@14485
   670
paulson@14485
   671
lemma atLeast_Suc_greaterThan: "atLeast (Suc k) = greaterThan k"
paulson@14485
   672
  by (auto simp add: greaterThan_def atLeast_def less_Suc_eq_le)
paulson@14485
   673
paulson@14485
   674
lemma UN_atLeast_UNIV: "(UN m::nat. atLeast m) = UNIV"
paulson@14485
   675
by blast
paulson@14485
   676
paulson@15047
   677
subsubsection {* The Constant @{term atMost} *}
paulson@15047
   678
paulson@14485
   679
lemma atMost_0 [simp]: "atMost (0::nat) = {0}"
paulson@14485
   680
by (simp add: atMost_def)
paulson@14485
   681
paulson@14485
   682
lemma atMost_Suc: "atMost (Suc k) = insert (Suc k) (atMost k)"
paulson@14485
   683
apply (simp add: atMost_def)
paulson@14485
   684
apply (simp add: less_Suc_eq order_le_less, blast)
paulson@14485
   685
done
paulson@14485
   686
paulson@14485
   687
lemma UN_atMost_UNIV: "(UN m::nat. atMost m) = UNIV"
paulson@14485
   688
by blast
paulson@14485
   689
paulson@15047
   690
subsubsection {* The Constant @{term atLeastLessThan} *}
paulson@15047
   691
nipkow@28068
   692
text{*The orientation of the following 2 rules is tricky. The lhs is
nipkow@24449
   693
defined in terms of the rhs.  Hence the chosen orientation makes sense
nipkow@24449
   694
in this theory --- the reverse orientation complicates proofs (eg
nipkow@24449
   695
nontermination). But outside, when the definition of the lhs is rarely
nipkow@24449
   696
used, the opposite orientation seems preferable because it reduces a
nipkow@24449
   697
specific concept to a more general one. *}
nipkow@28068
   698
paulson@15047
   699
lemma atLeast0LessThan: "{0::nat..<n} = {..<n}"
nipkow@15042
   700
by(simp add:lessThan_def atLeastLessThan_def)
nipkow@24449
   701
nipkow@28068
   702
lemma atLeast0AtMost: "{0..n::nat} = {..n}"
nipkow@28068
   703
by(simp add:atMost_def atLeastAtMost_def)
nipkow@28068
   704
haftmann@31998
   705
declare atLeast0LessThan[symmetric, code_unfold]
haftmann@31998
   706
        atLeast0AtMost[symmetric, code_unfold]
nipkow@24449
   707
nipkow@24449
   708
lemma atLeastLessThan0: "{m..<0::nat} = {}"
paulson@15047
   709
by (simp add: atLeastLessThan_def)
nipkow@24449
   710
paulson@15047
   711
subsubsection {* Intervals of nats with @{term Suc} *}
paulson@15047
   712
paulson@15047
   713
text{*Not a simprule because the RHS is too messy.*}
paulson@15047
   714
lemma atLeastLessThanSuc:
paulson@15047
   715
    "{m..<Suc n} = (if m \<le> n then insert n {m..<n} else {})"
paulson@15418
   716
by (auto simp add: atLeastLessThan_def)
paulson@15047
   717
paulson@15418
   718
lemma atLeastLessThan_singleton [simp]: "{m..<Suc m} = {m}"
paulson@15047
   719
by (auto simp add: atLeastLessThan_def)
nipkow@16041
   720
(*
paulson@15047
   721
lemma atLeast_sum_LessThan [simp]: "{m + k..<k::nat} = {}"
paulson@15047
   722
by (induct k, simp_all add: atLeastLessThanSuc)
paulson@15047
   723
paulson@15047
   724
lemma atLeastSucLessThan [simp]: "{Suc n..<n} = {}"
paulson@15047
   725
by (auto simp add: atLeastLessThan_def)
nipkow@16041
   726
*)
nipkow@15045
   727
lemma atLeastLessThanSuc_atLeastAtMost: "{l..<Suc u} = {l..u}"
paulson@14485
   728
  by (simp add: lessThan_Suc_atMost atLeastAtMost_def atLeastLessThan_def)
paulson@14485
   729
paulson@15418
   730
lemma atLeastSucAtMost_greaterThanAtMost: "{Suc l..u} = {l<..u}"
paulson@15418
   731
  by (simp add: atLeast_Suc_greaterThan atLeastAtMost_def
paulson@14485
   732
    greaterThanAtMost_def)
paulson@14485
   733
paulson@15418
   734
lemma atLeastSucLessThan_greaterThanLessThan: "{Suc l..<u} = {l<..<u}"
paulson@15418
   735
  by (simp add: atLeast_Suc_greaterThan atLeastLessThan_def
paulson@14485
   736
    greaterThanLessThan_def)
paulson@14485
   737
nipkow@15554
   738
lemma atLeastAtMostSuc_conv: "m \<le> Suc n \<Longrightarrow> {m..Suc n} = insert (Suc n) {m..n}"
nipkow@15554
   739
by (auto simp add: atLeastAtMost_def)
nipkow@15554
   740
noschinl@45932
   741
lemma atLeastAtMost_insertL: "m \<le> n \<Longrightarrow> insert m {Suc m..n} = {m ..n}"
noschinl@45932
   742
by auto
noschinl@45932
   743
kleing@43157
   744
text {* The analogous result is useful on @{typ int}: *}
kleing@43157
   745
(* here, because we don't have an own int section *)
kleing@43157
   746
lemma atLeastAtMostPlus1_int_conv:
kleing@43157
   747
  "m <= 1+n \<Longrightarrow> {m..1+n} = insert (1+n) {m..n::int}"
kleing@43157
   748
  by (auto intro: set_eqI)
kleing@43157
   749
paulson@33044
   750
lemma atLeastLessThan_add_Un: "i \<le> j \<Longrightarrow> {i..<j+k} = {i..<j} \<union> {j..<j+k::nat}"
paulson@33044
   751
  apply (induct k) 
paulson@33044
   752
  apply (simp_all add: atLeastLessThanSuc)   
paulson@33044
   753
  done
paulson@33044
   754
nipkow@16733
   755
subsubsection {* Image *}
nipkow@16733
   756
nipkow@16733
   757
lemma image_add_atLeastAtMost:
nipkow@16733
   758
  "(%n::nat. n+k) ` {i..j} = {i+k..j+k}" (is "?A = ?B")
nipkow@16733
   759
proof
nipkow@16733
   760
  show "?A \<subseteq> ?B" by auto
nipkow@16733
   761
next
nipkow@16733
   762
  show "?B \<subseteq> ?A"
nipkow@16733
   763
  proof
nipkow@16733
   764
    fix n assume a: "n : ?B"
webertj@20217
   765
    hence "n - k : {i..j}" by auto
nipkow@16733
   766
    moreover have "n = (n - k) + k" using a by auto
nipkow@16733
   767
    ultimately show "n : ?A" by blast
nipkow@16733
   768
  qed
nipkow@16733
   769
qed
nipkow@16733
   770
nipkow@16733
   771
lemma image_add_atLeastLessThan:
nipkow@16733
   772
  "(%n::nat. n+k) ` {i..<j} = {i+k..<j+k}" (is "?A = ?B")
nipkow@16733
   773
proof
nipkow@16733
   774
  show "?A \<subseteq> ?B" by auto
nipkow@16733
   775
next
nipkow@16733
   776
  show "?B \<subseteq> ?A"
nipkow@16733
   777
  proof
nipkow@16733
   778
    fix n assume a: "n : ?B"
webertj@20217
   779
    hence "n - k : {i..<j}" by auto
nipkow@16733
   780
    moreover have "n = (n - k) + k" using a by auto
nipkow@16733
   781
    ultimately show "n : ?A" by blast
nipkow@16733
   782
  qed
nipkow@16733
   783
qed
nipkow@16733
   784
nipkow@16733
   785
corollary image_Suc_atLeastAtMost[simp]:
nipkow@16733
   786
  "Suc ` {i..j} = {Suc i..Suc j}"
huffman@30079
   787
using image_add_atLeastAtMost[where k="Suc 0"] by simp
nipkow@16733
   788
nipkow@16733
   789
corollary image_Suc_atLeastLessThan[simp]:
nipkow@16733
   790
  "Suc ` {i..<j} = {Suc i..<Suc j}"
huffman@30079
   791
using image_add_atLeastLessThan[where k="Suc 0"] by simp
nipkow@16733
   792
nipkow@16733
   793
lemma image_add_int_atLeastLessThan:
nipkow@16733
   794
    "(%x. x + (l::int)) ` {0..<u-l} = {l..<u}"
nipkow@16733
   795
  apply (auto simp add: image_def)
nipkow@16733
   796
  apply (rule_tac x = "x - l" in bexI)
nipkow@16733
   797
  apply auto
nipkow@16733
   798
  done
nipkow@16733
   799
hoelzl@37664
   800
lemma image_minus_const_atLeastLessThan_nat:
hoelzl@37664
   801
  fixes c :: nat
hoelzl@37664
   802
  shows "(\<lambda>i. i - c) ` {x ..< y} =
hoelzl@37664
   803
      (if c < y then {x - c ..< y - c} else if x < y then {0} else {})"
hoelzl@37664
   804
    (is "_ = ?right")
hoelzl@37664
   805
proof safe
hoelzl@37664
   806
  fix a assume a: "a \<in> ?right"
hoelzl@37664
   807
  show "a \<in> (\<lambda>i. i - c) ` {x ..< y}"
hoelzl@37664
   808
  proof cases
hoelzl@37664
   809
    assume "c < y" with a show ?thesis
hoelzl@37664
   810
      by (auto intro!: image_eqI[of _ _ "a + c"])
hoelzl@37664
   811
  next
hoelzl@37664
   812
    assume "\<not> c < y" with a show ?thesis
hoelzl@37664
   813
      by (auto intro!: image_eqI[of _ _ x] split: split_if_asm)
hoelzl@37664
   814
  qed
hoelzl@37664
   815
qed auto
hoelzl@37664
   816
Andreas@51152
   817
lemma image_int_atLeastLessThan: "int ` {a..<b} = {int a..<int b}"
wenzelm@55143
   818
  by (auto intro!: image_eqI [where x = "nat x" for x])
Andreas@51152
   819
hoelzl@35580
   820
context ordered_ab_group_add
hoelzl@35580
   821
begin
hoelzl@35580
   822
hoelzl@35580
   823
lemma
hoelzl@35580
   824
  fixes x :: 'a
hoelzl@35580
   825
  shows image_uminus_greaterThan[simp]: "uminus ` {x<..} = {..<-x}"
hoelzl@35580
   826
  and image_uminus_atLeast[simp]: "uminus ` {x..} = {..-x}"
hoelzl@35580
   827
proof safe
hoelzl@35580
   828
  fix y assume "y < -x"
hoelzl@35580
   829
  hence *:  "x < -y" using neg_less_iff_less[of "-y" x] by simp
hoelzl@35580
   830
  have "- (-y) \<in> uminus ` {x<..}"
hoelzl@35580
   831
    by (rule imageI) (simp add: *)
hoelzl@35580
   832
  thus "y \<in> uminus ` {x<..}" by simp
hoelzl@35580
   833
next
hoelzl@35580
   834
  fix y assume "y \<le> -x"
hoelzl@35580
   835
  have "- (-y) \<in> uminus ` {x..}"
hoelzl@35580
   836
    by (rule imageI) (insert `y \<le> -x`[THEN le_imp_neg_le], simp)
hoelzl@35580
   837
  thus "y \<in> uminus ` {x..}" by simp
hoelzl@35580
   838
qed simp_all
hoelzl@35580
   839
hoelzl@35580
   840
lemma
hoelzl@35580
   841
  fixes x :: 'a
hoelzl@35580
   842
  shows image_uminus_lessThan[simp]: "uminus ` {..<x} = {-x<..}"
hoelzl@35580
   843
  and image_uminus_atMost[simp]: "uminus ` {..x} = {-x..}"
hoelzl@35580
   844
proof -
hoelzl@35580
   845
  have "uminus ` {..<x} = uminus ` uminus ` {-x<..}"
hoelzl@35580
   846
    and "uminus ` {..x} = uminus ` uminus ` {-x..}" by simp_all
hoelzl@35580
   847
  thus "uminus ` {..<x} = {-x<..}" and "uminus ` {..x} = {-x..}"
hoelzl@35580
   848
    by (simp_all add: image_image
hoelzl@35580
   849
        del: image_uminus_greaterThan image_uminus_atLeast)
hoelzl@35580
   850
qed
hoelzl@35580
   851
hoelzl@35580
   852
lemma
hoelzl@35580
   853
  fixes x :: 'a
hoelzl@35580
   854
  shows image_uminus_atLeastAtMost[simp]: "uminus ` {x..y} = {-y..-x}"
hoelzl@35580
   855
  and image_uminus_greaterThanAtMost[simp]: "uminus ` {x<..y} = {-y..<-x}"
hoelzl@35580
   856
  and image_uminus_atLeastLessThan[simp]: "uminus ` {x..<y} = {-y<..-x}"
hoelzl@35580
   857
  and image_uminus_greaterThanLessThan[simp]: "uminus ` {x<..<y} = {-y<..<-x}"
hoelzl@35580
   858
  by (simp_all add: atLeastAtMost_def greaterThanAtMost_def atLeastLessThan_def
hoelzl@35580
   859
      greaterThanLessThan_def image_Int[OF inj_uminus] Int_commute)
hoelzl@35580
   860
end
nipkow@16733
   861
paulson@14485
   862
subsubsection {* Finiteness *}
paulson@14485
   863
nipkow@15045
   864
lemma finite_lessThan [iff]: fixes k :: nat shows "finite {..<k}"
paulson@14485
   865
  by (induct k) (simp_all add: lessThan_Suc)
paulson@14485
   866
paulson@14485
   867
lemma finite_atMost [iff]: fixes k :: nat shows "finite {..k}"
paulson@14485
   868
  by (induct k) (simp_all add: atMost_Suc)
paulson@14485
   869
paulson@14485
   870
lemma finite_greaterThanLessThan [iff]:
nipkow@15045
   871
  fixes l :: nat shows "finite {l<..<u}"
paulson@14485
   872
by (simp add: greaterThanLessThan_def)
paulson@14485
   873
paulson@14485
   874
lemma finite_atLeastLessThan [iff]:
nipkow@15045
   875
  fixes l :: nat shows "finite {l..<u}"
paulson@14485
   876
by (simp add: atLeastLessThan_def)
paulson@14485
   877
paulson@14485
   878
lemma finite_greaterThanAtMost [iff]:
nipkow@15045
   879
  fixes l :: nat shows "finite {l<..u}"
paulson@14485
   880
by (simp add: greaterThanAtMost_def)
paulson@14485
   881
paulson@14485
   882
lemma finite_atLeastAtMost [iff]:
paulson@14485
   883
  fixes l :: nat shows "finite {l..u}"
paulson@14485
   884
by (simp add: atLeastAtMost_def)
paulson@14485
   885
nipkow@28068
   886
text {* A bounded set of natural numbers is finite. *}
paulson@14485
   887
lemma bounded_nat_set_is_finite:
nipkow@24853
   888
  "(ALL i:N. i < (n::nat)) ==> finite N"
nipkow@28068
   889
apply (rule finite_subset)
nipkow@28068
   890
 apply (rule_tac [2] finite_lessThan, auto)
nipkow@28068
   891
done
nipkow@28068
   892
nipkow@31044
   893
text {* A set of natural numbers is finite iff it is bounded. *}
nipkow@31044
   894
lemma finite_nat_set_iff_bounded:
nipkow@31044
   895
  "finite(N::nat set) = (EX m. ALL n:N. n<m)" (is "?F = ?B")
nipkow@31044
   896
proof
nipkow@31044
   897
  assume f:?F  show ?B
nipkow@31044
   898
    using Max_ge[OF `?F`, simplified less_Suc_eq_le[symmetric]] by blast
nipkow@31044
   899
next
nipkow@31044
   900
  assume ?B show ?F using `?B` by(blast intro:bounded_nat_set_is_finite)
nipkow@31044
   901
qed
nipkow@31044
   902
nipkow@31044
   903
lemma finite_nat_set_iff_bounded_le:
nipkow@31044
   904
  "finite(N::nat set) = (EX m. ALL n:N. n<=m)"
nipkow@31044
   905
apply(simp add:finite_nat_set_iff_bounded)
nipkow@31044
   906
apply(blast dest:less_imp_le_nat le_imp_less_Suc)
nipkow@31044
   907
done
nipkow@31044
   908
nipkow@28068
   909
lemma finite_less_ub:
nipkow@28068
   910
     "!!f::nat=>nat. (!!n. n \<le> f n) ==> finite {n. f n \<le> u}"
nipkow@28068
   911
by (rule_tac B="{..u}" in finite_subset, auto intro: order_trans)
paulson@14485
   912
hoelzl@56328
   913
nipkow@24853
   914
text{* Any subset of an interval of natural numbers the size of the
nipkow@24853
   915
subset is exactly that interval. *}
nipkow@24853
   916
nipkow@24853
   917
lemma subset_card_intvl_is_intvl:
blanchet@55085
   918
  assumes "A \<subseteq> {k..<k + card A}"
blanchet@55085
   919
  shows "A = {k..<k + card A}"
wenzelm@53374
   920
proof (cases "finite A")
wenzelm@53374
   921
  case True
wenzelm@53374
   922
  from this and assms show ?thesis
wenzelm@53374
   923
  proof (induct A rule: finite_linorder_max_induct)
nipkow@24853
   924
    case empty thus ?case by auto
nipkow@24853
   925
  next
nipkow@33434
   926
    case (insert b A)
wenzelm@53374
   927
    hence *: "b \<notin> A" by auto
blanchet@55085
   928
    with insert have "A <= {k..<k + card A}" and "b = k + card A"
wenzelm@53374
   929
      by fastforce+
wenzelm@53374
   930
    with insert * show ?case by auto
nipkow@24853
   931
  qed
nipkow@24853
   932
next
wenzelm@53374
   933
  case False
wenzelm@53374
   934
  with assms show ?thesis by simp
nipkow@24853
   935
qed
nipkow@24853
   936
nipkow@24853
   937
paulson@32596
   938
subsubsection {* Proving Inclusions and Equalities between Unions *}
paulson@32596
   939
nipkow@36755
   940
lemma UN_le_eq_Un0:
nipkow@36755
   941
  "(\<Union>i\<le>n::nat. M i) = (\<Union>i\<in>{1..n}. M i) \<union> M 0" (is "?A = ?B")
nipkow@36755
   942
proof
nipkow@36755
   943
  show "?A <= ?B"
nipkow@36755
   944
  proof
nipkow@36755
   945
    fix x assume "x : ?A"
nipkow@36755
   946
    then obtain i where i: "i\<le>n" "x : M i" by auto
nipkow@36755
   947
    show "x : ?B"
nipkow@36755
   948
    proof(cases i)
nipkow@36755
   949
      case 0 with i show ?thesis by simp
nipkow@36755
   950
    next
nipkow@36755
   951
      case (Suc j) with i show ?thesis by auto
nipkow@36755
   952
    qed
nipkow@36755
   953
  qed
nipkow@36755
   954
next
nipkow@36755
   955
  show "?B <= ?A" by auto
nipkow@36755
   956
qed
nipkow@36755
   957
nipkow@36755
   958
lemma UN_le_add_shift:
nipkow@36755
   959
  "(\<Union>i\<le>n::nat. M(i+k)) = (\<Union>i\<in>{k..n+k}. M i)" (is "?A = ?B")
nipkow@36755
   960
proof
nipkow@44890
   961
  show "?A <= ?B" by fastforce
nipkow@36755
   962
next
nipkow@36755
   963
  show "?B <= ?A"
nipkow@36755
   964
  proof
nipkow@36755
   965
    fix x assume "x : ?B"
nipkow@36755
   966
    then obtain i where i: "i : {k..n+k}" "x : M(i)" by auto
nipkow@36755
   967
    hence "i-k\<le>n & x : M((i-k)+k)" by auto
nipkow@36755
   968
    thus "x : ?A" by blast
nipkow@36755
   969
  qed
nipkow@36755
   970
qed
nipkow@36755
   971
paulson@32596
   972
lemma UN_UN_finite_eq: "(\<Union>n::nat. \<Union>i\<in>{0..<n}. A i) = (\<Union>n. A n)"
paulson@32596
   973
  by (auto simp add: atLeast0LessThan) 
paulson@32596
   974
paulson@32596
   975
lemma UN_finite_subset: "(!!n::nat. (\<Union>i\<in>{0..<n}. A i) \<subseteq> C) \<Longrightarrow> (\<Union>n. A n) \<subseteq> C"
paulson@32596
   976
  by (subst UN_UN_finite_eq [symmetric]) blast
paulson@32596
   977
paulson@33044
   978
lemma UN_finite2_subset: 
paulson@33044
   979
     "(!!n::nat. (\<Union>i\<in>{0..<n}. A i) \<subseteq> (\<Union>i\<in>{0..<n+k}. B i)) \<Longrightarrow> (\<Union>n. A n) \<subseteq> (\<Union>n. B n)"
paulson@33044
   980
  apply (rule UN_finite_subset)
paulson@33044
   981
  apply (subst UN_UN_finite_eq [symmetric, of B]) 
paulson@33044
   982
  apply blast
paulson@33044
   983
  done
paulson@32596
   984
paulson@32596
   985
lemma UN_finite2_eq:
paulson@33044
   986
  "(!!n::nat. (\<Union>i\<in>{0..<n}. A i) = (\<Union>i\<in>{0..<n+k}. B i)) \<Longrightarrow> (\<Union>n. A n) = (\<Union>n. B n)"
paulson@33044
   987
  apply (rule subset_antisym)
paulson@33044
   988
   apply (rule UN_finite2_subset, blast)
paulson@33044
   989
 apply (rule UN_finite2_subset [where k=k])
huffman@35216
   990
 apply (force simp add: atLeastLessThan_add_Un [of 0])
paulson@33044
   991
 done
paulson@32596
   992
paulson@32596
   993
paulson@14485
   994
subsubsection {* Cardinality *}
paulson@14485
   995
nipkow@15045
   996
lemma card_lessThan [simp]: "card {..<u} = u"
paulson@15251
   997
  by (induct u, simp_all add: lessThan_Suc)
paulson@14485
   998
paulson@14485
   999
lemma card_atMost [simp]: "card {..u} = Suc u"
paulson@14485
  1000
  by (simp add: lessThan_Suc_atMost [THEN sym])
paulson@14485
  1001
nipkow@15045
  1002
lemma card_atLeastLessThan [simp]: "card {l..<u} = u - l"
nipkow@15045
  1003
  apply (subgoal_tac "card {l..<u} = card {..<u-l}")
paulson@14485
  1004
  apply (erule ssubst, rule card_lessThan)
nipkow@15045
  1005
  apply (subgoal_tac "(%x. x + l) ` {..<u-l} = {l..<u}")
paulson@14485
  1006
  apply (erule subst)
paulson@14485
  1007
  apply (rule card_image)
paulson@14485
  1008
  apply (simp add: inj_on_def)
paulson@14485
  1009
  apply (auto simp add: image_def atLeastLessThan_def lessThan_def)
paulson@14485
  1010
  apply (rule_tac x = "x - l" in exI)
paulson@14485
  1011
  apply arith
paulson@14485
  1012
  done
paulson@14485
  1013
paulson@15418
  1014
lemma card_atLeastAtMost [simp]: "card {l..u} = Suc u - l"
paulson@14485
  1015
  by (subst atLeastLessThanSuc_atLeastAtMost [THEN sym], simp)
paulson@14485
  1016
paulson@15418
  1017
lemma card_greaterThanAtMost [simp]: "card {l<..u} = u - l"
paulson@14485
  1018
  by (subst atLeastSucAtMost_greaterThanAtMost [THEN sym], simp)
paulson@14485
  1019
nipkow@15045
  1020
lemma card_greaterThanLessThan [simp]: "card {l<..<u} = u - Suc l"
paulson@14485
  1021
  by (subst atLeastSucLessThan_greaterThanLessThan [THEN sym], simp)
paulson@14485
  1022
nipkow@26105
  1023
lemma ex_bij_betw_nat_finite:
nipkow@26105
  1024
  "finite M \<Longrightarrow> \<exists>h. bij_betw h {0..<card M} M"
nipkow@26105
  1025
apply(drule finite_imp_nat_seg_image_inj_on)
nipkow@26105
  1026
apply(auto simp:atLeast0LessThan[symmetric] lessThan_def[symmetric] card_image bij_betw_def)
nipkow@26105
  1027
done
nipkow@26105
  1028
nipkow@26105
  1029
lemma ex_bij_betw_finite_nat:
nipkow@26105
  1030
  "finite M \<Longrightarrow> \<exists>h. bij_betw h M {0..<card M}"
nipkow@26105
  1031
by (blast dest: ex_bij_betw_nat_finite bij_betw_inv)
nipkow@26105
  1032
nipkow@31438
  1033
lemma finite_same_card_bij:
nipkow@31438
  1034
  "finite A \<Longrightarrow> finite B \<Longrightarrow> card A = card B \<Longrightarrow> EX h. bij_betw h A B"
nipkow@31438
  1035
apply(drule ex_bij_betw_finite_nat)
nipkow@31438
  1036
apply(drule ex_bij_betw_nat_finite)
nipkow@31438
  1037
apply(auto intro!:bij_betw_trans)
nipkow@31438
  1038
done
nipkow@31438
  1039
nipkow@31438
  1040
lemma ex_bij_betw_nat_finite_1:
nipkow@31438
  1041
  "finite M \<Longrightarrow> \<exists>h. bij_betw h {1 .. card M} M"
nipkow@31438
  1042
by (rule finite_same_card_bij) auto
nipkow@31438
  1043
hoelzl@40703
  1044
lemma bij_betw_iff_card:
hoelzl@40703
  1045
  assumes FIN: "finite A" and FIN': "finite B"
hoelzl@40703
  1046
  shows BIJ: "(\<exists>f. bij_betw f A B) \<longleftrightarrow> (card A = card B)"
hoelzl@40703
  1047
using assms
hoelzl@40703
  1048
proof(auto simp add: bij_betw_same_card)
hoelzl@40703
  1049
  assume *: "card A = card B"
hoelzl@40703
  1050
  obtain f where "bij_betw f A {0 ..< card A}"
hoelzl@40703
  1051
  using FIN ex_bij_betw_finite_nat by blast
hoelzl@40703
  1052
  moreover obtain g where "bij_betw g {0 ..< card B} B"
hoelzl@40703
  1053
  using FIN' ex_bij_betw_nat_finite by blast
hoelzl@40703
  1054
  ultimately have "bij_betw (g o f) A B"
hoelzl@40703
  1055
  using * by (auto simp add: bij_betw_trans)
hoelzl@40703
  1056
  thus "(\<exists>f. bij_betw f A B)" by blast
hoelzl@40703
  1057
qed
hoelzl@40703
  1058
hoelzl@40703
  1059
lemma inj_on_iff_card_le:
hoelzl@40703
  1060
  assumes FIN: "finite A" and FIN': "finite B"
hoelzl@40703
  1061
  shows "(\<exists>f. inj_on f A \<and> f ` A \<le> B) = (card A \<le> card B)"
hoelzl@40703
  1062
proof (safe intro!: card_inj_on_le)
hoelzl@40703
  1063
  assume *: "card A \<le> card B"
hoelzl@40703
  1064
  obtain f where 1: "inj_on f A" and 2: "f ` A = {0 ..< card A}"
hoelzl@40703
  1065
  using FIN ex_bij_betw_finite_nat unfolding bij_betw_def by force
hoelzl@40703
  1066
  moreover obtain g where "inj_on g {0 ..< card B}" and 3: "g ` {0 ..< card B} = B"
hoelzl@40703
  1067
  using FIN' ex_bij_betw_nat_finite unfolding bij_betw_def by force
hoelzl@40703
  1068
  ultimately have "inj_on g (f ` A)" using subset_inj_on[of g _ "f ` A"] * by force
hoelzl@40703
  1069
  hence "inj_on (g o f) A" using 1 comp_inj_on by blast
hoelzl@40703
  1070
  moreover
hoelzl@40703
  1071
  {have "{0 ..< card A} \<le> {0 ..< card B}" using * by force
hoelzl@40703
  1072
   with 2 have "f ` A  \<le> {0 ..< card B}" by blast
hoelzl@40703
  1073
   hence "(g o f) ` A \<le> B" unfolding comp_def using 3 by force
hoelzl@40703
  1074
  }
hoelzl@40703
  1075
  ultimately show "(\<exists>f. inj_on f A \<and> f ` A \<le> B)" by blast
hoelzl@40703
  1076
qed (insert assms, auto)
nipkow@26105
  1077
paulson@14485
  1078
subsection {* Intervals of integers *}
paulson@14485
  1079
nipkow@15045
  1080
lemma atLeastLessThanPlusOne_atLeastAtMost_int: "{l..<u+1} = {l..(u::int)}"
paulson@14485
  1081
  by (auto simp add: atLeastAtMost_def atLeastLessThan_def)
paulson@14485
  1082
paulson@15418
  1083
lemma atLeastPlusOneAtMost_greaterThanAtMost_int: "{l+1..u} = {l<..(u::int)}"
paulson@14485
  1084
  by (auto simp add: atLeastAtMost_def greaterThanAtMost_def)
paulson@14485
  1085
paulson@15418
  1086
lemma atLeastPlusOneLessThan_greaterThanLessThan_int:
paulson@15418
  1087
    "{l+1..<u} = {l<..<u::int}"
paulson@14485
  1088
  by (auto simp add: atLeastLessThan_def greaterThanLessThan_def)
paulson@14485
  1089
paulson@14485
  1090
subsubsection {* Finiteness *}
paulson@14485
  1091
paulson@15418
  1092
lemma image_atLeastZeroLessThan_int: "0 \<le> u ==>
nipkow@15045
  1093
    {(0::int)..<u} = int ` {..<nat u}"
paulson@14485
  1094
  apply (unfold image_def lessThan_def)
paulson@14485
  1095
  apply auto
paulson@14485
  1096
  apply (rule_tac x = "nat x" in exI)
huffman@35216
  1097
  apply (auto simp add: zless_nat_eq_int_zless [THEN sym])
paulson@14485
  1098
  done
paulson@14485
  1099
nipkow@15045
  1100
lemma finite_atLeastZeroLessThan_int: "finite {(0::int)..<u}"
wenzelm@47988
  1101
  apply (cases "0 \<le> u")
paulson@14485
  1102
  apply (subst image_atLeastZeroLessThan_int, assumption)
paulson@14485
  1103
  apply (rule finite_imageI)
paulson@14485
  1104
  apply auto
paulson@14485
  1105
  done
paulson@14485
  1106
nipkow@15045
  1107
lemma finite_atLeastLessThan_int [iff]: "finite {l..<u::int}"
nipkow@15045
  1108
  apply (subgoal_tac "(%x. x + l) ` {0..<u-l} = {l..<u}")
paulson@14485
  1109
  apply (erule subst)
paulson@14485
  1110
  apply (rule finite_imageI)
paulson@14485
  1111
  apply (rule finite_atLeastZeroLessThan_int)
nipkow@16733
  1112
  apply (rule image_add_int_atLeastLessThan)
paulson@14485
  1113
  done
paulson@14485
  1114
paulson@15418
  1115
lemma finite_atLeastAtMost_int [iff]: "finite {l..(u::int)}"
paulson@14485
  1116
  by (subst atLeastLessThanPlusOne_atLeastAtMost_int [THEN sym], simp)
paulson@14485
  1117
paulson@15418
  1118
lemma finite_greaterThanAtMost_int [iff]: "finite {l<..(u::int)}"
paulson@14485
  1119
  by (subst atLeastPlusOneAtMost_greaterThanAtMost_int [THEN sym], simp)
paulson@14485
  1120
paulson@15418
  1121
lemma finite_greaterThanLessThan_int [iff]: "finite {l<..<u::int}"
paulson@14485
  1122
  by (subst atLeastPlusOneLessThan_greaterThanLessThan_int [THEN sym], simp)
paulson@14485
  1123
nipkow@24853
  1124
paulson@14485
  1125
subsubsection {* Cardinality *}
paulson@14485
  1126
nipkow@15045
  1127
lemma card_atLeastZeroLessThan_int: "card {(0::int)..<u} = nat u"
wenzelm@47988
  1128
  apply (cases "0 \<le> u")
paulson@14485
  1129
  apply (subst image_atLeastZeroLessThan_int, assumption)
paulson@14485
  1130
  apply (subst card_image)
paulson@14485
  1131
  apply (auto simp add: inj_on_def)
paulson@14485
  1132
  done
paulson@14485
  1133
nipkow@15045
  1134
lemma card_atLeastLessThan_int [simp]: "card {l..<u} = nat (u - l)"
nipkow@15045
  1135
  apply (subgoal_tac "card {l..<u} = card {0..<u-l}")
paulson@14485
  1136
  apply (erule ssubst, rule card_atLeastZeroLessThan_int)
nipkow@15045
  1137
  apply (subgoal_tac "(%x. x + l) ` {0..<u-l} = {l..<u}")
paulson@14485
  1138
  apply (erule subst)
paulson@14485
  1139
  apply (rule card_image)
paulson@14485
  1140
  apply (simp add: inj_on_def)
nipkow@16733
  1141
  apply (rule image_add_int_atLeastLessThan)
paulson@14485
  1142
  done
paulson@14485
  1143
paulson@14485
  1144
lemma card_atLeastAtMost_int [simp]: "card {l..u} = nat (u - l + 1)"
nipkow@29667
  1145
apply (subst atLeastLessThanPlusOne_atLeastAtMost_int [THEN sym])
nipkow@29667
  1146
apply (auto simp add: algebra_simps)
nipkow@29667
  1147
done
paulson@14485
  1148
paulson@15418
  1149
lemma card_greaterThanAtMost_int [simp]: "card {l<..u} = nat (u - l)"
nipkow@29667
  1150
by (subst atLeastPlusOneAtMost_greaterThanAtMost_int [THEN sym], simp)
paulson@14485
  1151
nipkow@15045
  1152
lemma card_greaterThanLessThan_int [simp]: "card {l<..<u} = nat (u - (l + 1))"
nipkow@29667
  1153
by (subst atLeastPlusOneLessThan_greaterThanLessThan_int [THEN sym], simp)
paulson@14485
  1154
bulwahn@27656
  1155
lemma finite_M_bounded_by_nat: "finite {k. P k \<and> k < (i::nat)}"
bulwahn@27656
  1156
proof -
bulwahn@27656
  1157
  have "{k. P k \<and> k < i} \<subseteq> {..<i}" by auto
bulwahn@27656
  1158
  with finite_lessThan[of "i"] show ?thesis by (simp add: finite_subset)
bulwahn@27656
  1159
qed
bulwahn@27656
  1160
bulwahn@27656
  1161
lemma card_less:
bulwahn@27656
  1162
assumes zero_in_M: "0 \<in> M"
bulwahn@27656
  1163
shows "card {k \<in> M. k < Suc i} \<noteq> 0"
bulwahn@27656
  1164
proof -
bulwahn@27656
  1165
  from zero_in_M have "{k \<in> M. k < Suc i} \<noteq> {}" by auto
bulwahn@27656
  1166
  with finite_M_bounded_by_nat show ?thesis by (auto simp add: card_eq_0_iff)
bulwahn@27656
  1167
qed
bulwahn@27656
  1168
bulwahn@27656
  1169
lemma card_less_Suc2: "0 \<notin> M \<Longrightarrow> card {k. Suc k \<in> M \<and> k < i} = card {k \<in> M. k < Suc i}"
haftmann@37388
  1170
apply (rule card_bij_eq [of Suc _ _ "\<lambda>x. x - Suc 0"])
bulwahn@27656
  1171
apply simp
nipkow@44890
  1172
apply fastforce
bulwahn@27656
  1173
apply auto
bulwahn@27656
  1174
apply (rule inj_on_diff_nat)
bulwahn@27656
  1175
apply auto
bulwahn@27656
  1176
apply (case_tac x)
bulwahn@27656
  1177
apply auto
bulwahn@27656
  1178
apply (case_tac xa)
bulwahn@27656
  1179
apply auto
bulwahn@27656
  1180
apply (case_tac xa)
bulwahn@27656
  1181
apply auto
bulwahn@27656
  1182
done
bulwahn@27656
  1183
bulwahn@27656
  1184
lemma card_less_Suc:
bulwahn@27656
  1185
  assumes zero_in_M: "0 \<in> M"
bulwahn@27656
  1186
    shows "Suc (card {k. Suc k \<in> M \<and> k < i}) = card {k \<in> M. k < Suc i}"
bulwahn@27656
  1187
proof -
bulwahn@27656
  1188
  from assms have a: "0 \<in> {k \<in> M. k < Suc i}" by simp
bulwahn@27656
  1189
  hence c: "{k \<in> M. k < Suc i} = insert 0 ({k \<in> M. k < Suc i} - {0})"
bulwahn@27656
  1190
    by (auto simp only: insert_Diff)
bulwahn@27656
  1191
  have b: "{k \<in> M. k < Suc i} - {0} = {k \<in> M - {0}. k < Suc i}"  by auto
bulwahn@27656
  1192
  from finite_M_bounded_by_nat[of "\<lambda>x. x \<in> M" "Suc i"] have "Suc (card {k. Suc k \<in> M \<and> k < i}) = card (insert 0 ({k \<in> M. k < Suc i} - {0}))"
bulwahn@27656
  1193
    apply (subst card_insert)
bulwahn@27656
  1194
    apply simp_all
bulwahn@27656
  1195
    apply (subst b)
bulwahn@27656
  1196
    apply (subst card_less_Suc2[symmetric])
bulwahn@27656
  1197
    apply simp_all
bulwahn@27656
  1198
    done
bulwahn@27656
  1199
  with c show ?thesis by simp
bulwahn@27656
  1200
qed
bulwahn@27656
  1201
paulson@14485
  1202
paulson@13850
  1203
subsection {*Lemmas useful with the summation operator setsum*}
paulson@13850
  1204
ballarin@16102
  1205
text {* For examples, see Algebra/poly/UnivPoly2.thy *}
ballarin@13735
  1206
wenzelm@14577
  1207
subsubsection {* Disjoint Unions *}
ballarin@13735
  1208
wenzelm@14577
  1209
text {* Singletons and open intervals *}
ballarin@13735
  1210
ballarin@13735
  1211
lemma ivl_disj_un_singleton:
nipkow@15045
  1212
  "{l::'a::linorder} Un {l<..} = {l..}"
nipkow@15045
  1213
  "{..<u} Un {u::'a::linorder} = {..u}"
nipkow@15045
  1214
  "(l::'a::linorder) < u ==> {l} Un {l<..<u} = {l..<u}"
nipkow@15045
  1215
  "(l::'a::linorder) < u ==> {l<..<u} Un {u} = {l<..u}"
nipkow@15045
  1216
  "(l::'a::linorder) <= u ==> {l} Un {l<..u} = {l..u}"
nipkow@15045
  1217
  "(l::'a::linorder) <= u ==> {l..<u} Un {u} = {l..u}"
ballarin@14398
  1218
by auto
ballarin@13735
  1219
wenzelm@14577
  1220
text {* One- and two-sided intervals *}
ballarin@13735
  1221
ballarin@13735
  1222
lemma ivl_disj_un_one:
nipkow@15045
  1223
  "(l::'a::linorder) < u ==> {..l} Un {l<..<u} = {..<u}"
nipkow@15045
  1224
  "(l::'a::linorder) <= u ==> {..<l} Un {l..<u} = {..<u}"
nipkow@15045
  1225
  "(l::'a::linorder) <= u ==> {..l} Un {l<..u} = {..u}"
nipkow@15045
  1226
  "(l::'a::linorder) <= u ==> {..<l} Un {l..u} = {..u}"
nipkow@15045
  1227
  "(l::'a::linorder) <= u ==> {l<..u} Un {u<..} = {l<..}"
nipkow@15045
  1228
  "(l::'a::linorder) < u ==> {l<..<u} Un {u..} = {l<..}"
nipkow@15045
  1229
  "(l::'a::linorder) <= u ==> {l..u} Un {u<..} = {l..}"
nipkow@15045
  1230
  "(l::'a::linorder) <= u ==> {l..<u} Un {u..} = {l..}"
ballarin@14398
  1231
by auto
ballarin@13735
  1232
wenzelm@14577
  1233
text {* Two- and two-sided intervals *}
ballarin@13735
  1234
ballarin@13735
  1235
lemma ivl_disj_un_two:
nipkow@15045
  1236
  "[| (l::'a::linorder) < m; m <= u |] ==> {l<..<m} Un {m..<u} = {l<..<u}"
nipkow@15045
  1237
  "[| (l::'a::linorder) <= m; m < u |] ==> {l<..m} Un {m<..<u} = {l<..<u}"
nipkow@15045
  1238
  "[| (l::'a::linorder) <= m; m <= u |] ==> {l..<m} Un {m..<u} = {l..<u}"
nipkow@15045
  1239
  "[| (l::'a::linorder) <= m; m < u |] ==> {l..m} Un {m<..<u} = {l..<u}"
nipkow@15045
  1240
  "[| (l::'a::linorder) < m; m <= u |] ==> {l<..<m} Un {m..u} = {l<..u}"
nipkow@15045
  1241
  "[| (l::'a::linorder) <= m; m <= u |] ==> {l<..m} Un {m<..u} = {l<..u}"
nipkow@15045
  1242
  "[| (l::'a::linorder) <= m; m <= u |] ==> {l..<m} Un {m..u} = {l..u}"
nipkow@15045
  1243
  "[| (l::'a::linorder) <= m; m <= u |] ==> {l..m} Un {m<..u} = {l..u}"
ballarin@14398
  1244
by auto
ballarin@13735
  1245
ballarin@13735
  1246
lemmas ivl_disj_un = ivl_disj_un_singleton ivl_disj_un_one ivl_disj_un_two
ballarin@13735
  1247
wenzelm@14577
  1248
subsubsection {* Disjoint Intersections *}
ballarin@13735
  1249
wenzelm@14577
  1250
text {* One- and two-sided intervals *}
ballarin@13735
  1251
ballarin@13735
  1252
lemma ivl_disj_int_one:
nipkow@15045
  1253
  "{..l::'a::order} Int {l<..<u} = {}"
nipkow@15045
  1254
  "{..<l} Int {l..<u} = {}"
nipkow@15045
  1255
  "{..l} Int {l<..u} = {}"
nipkow@15045
  1256
  "{..<l} Int {l..u} = {}"
nipkow@15045
  1257
  "{l<..u} Int {u<..} = {}"
nipkow@15045
  1258
  "{l<..<u} Int {u..} = {}"
nipkow@15045
  1259
  "{l..u} Int {u<..} = {}"
nipkow@15045
  1260
  "{l..<u} Int {u..} = {}"
ballarin@14398
  1261
  by auto
ballarin@13735
  1262
wenzelm@14577
  1263
text {* Two- and two-sided intervals *}
ballarin@13735
  1264
ballarin@13735
  1265
lemma ivl_disj_int_two:
nipkow@15045
  1266
  "{l::'a::order<..<m} Int {m..<u} = {}"
nipkow@15045
  1267
  "{l<..m} Int {m<..<u} = {}"
nipkow@15045
  1268
  "{l..<m} Int {m..<u} = {}"
nipkow@15045
  1269
  "{l..m} Int {m<..<u} = {}"
nipkow@15045
  1270
  "{l<..<m} Int {m..u} = {}"
nipkow@15045
  1271
  "{l<..m} Int {m<..u} = {}"
nipkow@15045
  1272
  "{l..<m} Int {m..u} = {}"
nipkow@15045
  1273
  "{l..m} Int {m<..u} = {}"
ballarin@14398
  1274
  by auto
ballarin@13735
  1275
nipkow@32456
  1276
lemmas ivl_disj_int = ivl_disj_int_one ivl_disj_int_two
ballarin@13735
  1277
nipkow@15542
  1278
subsubsection {* Some Differences *}
nipkow@15542
  1279
nipkow@15542
  1280
lemma ivl_diff[simp]:
nipkow@15542
  1281
 "i \<le> n \<Longrightarrow> {i..<m} - {i..<n} = {n..<(m::'a::linorder)}"
nipkow@15542
  1282
by(auto)
nipkow@15542
  1283
hoelzl@56194
  1284
lemma (in linorder) lessThan_minus_lessThan [simp]:
hoelzl@56194
  1285
  "{..< n} - {..< m} = {m ..< n}"
hoelzl@56194
  1286
  by auto
hoelzl@56194
  1287
nipkow@15542
  1288
nipkow@15542
  1289
subsubsection {* Some Subset Conditions *}
nipkow@15542
  1290
blanchet@54147
  1291
lemma ivl_subset [simp]:
nipkow@15542
  1292
 "({i..<j} \<subseteq> {m..<n}) = (j \<le> i | m \<le> i & j \<le> (n::'a::linorder))"
nipkow@15542
  1293
apply(auto simp:linorder_not_le)
nipkow@15542
  1294
apply(rule ccontr)
nipkow@15542
  1295
apply(insert linorder_le_less_linear[of i n])
nipkow@15542
  1296
apply(clarsimp simp:linorder_not_le)
nipkow@44890
  1297
apply(fastforce)
nipkow@15542
  1298
done
nipkow@15542
  1299
nipkow@15041
  1300
nipkow@15042
  1301
subsection {* Summation indexed over intervals *}
nipkow@15042
  1302
nipkow@15042
  1303
syntax
nipkow@15042
  1304
  "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _ = _.._./ _)" [0,0,0,10] 10)
nipkow@15048
  1305
  "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _ = _..<_./ _)" [0,0,0,10] 10)
nipkow@16052
  1306
  "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _<_./ _)" [0,0,10] 10)
nipkow@16052
  1307
  "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _<=_./ _)" [0,0,10] 10)
nipkow@15042
  1308
syntax (xsymbols)
nipkow@15042
  1309
  "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _.._./ _)" [0,0,0,10] 10)
nipkow@15048
  1310
  "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _..<_./ _)" [0,0,0,10] 10)
nipkow@16052
  1311
  "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_<_./ _)" [0,0,10] 10)
nipkow@16052
  1312
  "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_\<le>_./ _)" [0,0,10] 10)
nipkow@15042
  1313
syntax (HTML output)
nipkow@15042
  1314
  "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _.._./ _)" [0,0,0,10] 10)
nipkow@15048
  1315
  "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _..<_./ _)" [0,0,0,10] 10)
nipkow@16052
  1316
  "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_<_./ _)" [0,0,10] 10)
nipkow@16052
  1317
  "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_\<le>_./ _)" [0,0,10] 10)
nipkow@15056
  1318
syntax (latex_sum output)
nipkow@15052
  1319
  "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
nipkow@15052
  1320
 ("(3\<^raw:$\sum_{>_ = _\<^raw:}^{>_\<^raw:}$> _)" [0,0,0,10] 10)
nipkow@15052
  1321
  "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
nipkow@15052
  1322
 ("(3\<^raw:$\sum_{>_ = _\<^raw:}^{<>_\<^raw:}$> _)" [0,0,0,10] 10)
nipkow@16052
  1323
  "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
nipkow@16052
  1324
 ("(3\<^raw:$\sum_{>_ < _\<^raw:}$> _)" [0,0,10] 10)
nipkow@15052
  1325
  "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
nipkow@16052
  1326
 ("(3\<^raw:$\sum_{>_ \<le> _\<^raw:}$> _)" [0,0,10] 10)
nipkow@15041
  1327
nipkow@15048
  1328
translations
nipkow@28853
  1329
  "\<Sum>x=a..b. t" == "CONST setsum (%x. t) {a..b}"
nipkow@28853
  1330
  "\<Sum>x=a..<b. t" == "CONST setsum (%x. t) {a..<b}"
nipkow@28853
  1331
  "\<Sum>i\<le>n. t" == "CONST setsum (\<lambda>i. t) {..n}"
nipkow@28853
  1332
  "\<Sum>i<n. t" == "CONST setsum (\<lambda>i. t) {..<n}"
nipkow@15041
  1333
nipkow@15052
  1334
text{* The above introduces some pretty alternative syntaxes for
nipkow@15056
  1335
summation over intervals:
nipkow@15052
  1336
\begin{center}
nipkow@15052
  1337
\begin{tabular}{lll}
nipkow@15056
  1338
Old & New & \LaTeX\\
nipkow@15056
  1339
@{term[source]"\<Sum>x\<in>{a..b}. e"} & @{term"\<Sum>x=a..b. e"} & @{term[mode=latex_sum]"\<Sum>x=a..b. e"}\\
nipkow@15056
  1340
@{term[source]"\<Sum>x\<in>{a..<b}. e"} & @{term"\<Sum>x=a..<b. e"} & @{term[mode=latex_sum]"\<Sum>x=a..<b. e"}\\
nipkow@16052
  1341
@{term[source]"\<Sum>x\<in>{..b}. e"} & @{term"\<Sum>x\<le>b. e"} & @{term[mode=latex_sum]"\<Sum>x\<le>b. e"}\\
nipkow@15056
  1342
@{term[source]"\<Sum>x\<in>{..<b}. e"} & @{term"\<Sum>x<b. e"} & @{term[mode=latex_sum]"\<Sum>x<b. e"}
nipkow@15052
  1343
\end{tabular}
nipkow@15052
  1344
\end{center}
nipkow@15056
  1345
The left column shows the term before introduction of the new syntax,
nipkow@15056
  1346
the middle column shows the new (default) syntax, and the right column
nipkow@15056
  1347
shows a special syntax. The latter is only meaningful for latex output
nipkow@15056
  1348
and has to be activated explicitly by setting the print mode to
wenzelm@21502
  1349
@{text latex_sum} (e.g.\ via @{text "mode = latex_sum"} in
nipkow@15056
  1350
antiquotations). It is not the default \LaTeX\ output because it only
nipkow@15056
  1351
works well with italic-style formulae, not tt-style.
nipkow@15052
  1352
nipkow@15052
  1353
Note that for uniformity on @{typ nat} it is better to use
nipkow@15052
  1354
@{term"\<Sum>x::nat=0..<n. e"} rather than @{text"\<Sum>x<n. e"}: @{text setsum} may
nipkow@15052
  1355
not provide all lemmas available for @{term"{m..<n}"} also in the
nipkow@15052
  1356
special form for @{term"{..<n}"}. *}
nipkow@15052
  1357
nipkow@15542
  1358
text{* This congruence rule should be used for sums over intervals as
nipkow@15542
  1359
the standard theorem @{text[source]setsum_cong} does not work well
nipkow@15542
  1360
with the simplifier who adds the unsimplified premise @{term"x:B"} to
nipkow@15542
  1361
the context. *}
nipkow@15542
  1362
nipkow@15542
  1363
lemma setsum_ivl_cong:
nipkow@15542
  1364
 "\<lbrakk>a = c; b = d; !!x. \<lbrakk> c \<le> x; x < d \<rbrakk> \<Longrightarrow> f x = g x \<rbrakk> \<Longrightarrow>
nipkow@15542
  1365
 setsum f {a..<b} = setsum g {c..<d}"
nipkow@15542
  1366
by(rule setsum_cong, simp_all)
nipkow@15041
  1367
nipkow@16041
  1368
(* FIXME why are the following simp rules but the corresponding eqns
nipkow@16041
  1369
on intervals are not? *)
nipkow@16041
  1370
nipkow@16052
  1371
lemma setsum_atMost_Suc[simp]: "(\<Sum>i \<le> Suc n. f i) = (\<Sum>i \<le> n. f i) + f(Suc n)"
nipkow@16052
  1372
by (simp add:atMost_Suc add_ac)
nipkow@16052
  1373
nipkow@16041
  1374
lemma setsum_lessThan_Suc[simp]: "(\<Sum>i < Suc n. f i) = (\<Sum>i < n. f i) + f n"
nipkow@16041
  1375
by (simp add:lessThan_Suc add_ac)
nipkow@15041
  1376
nipkow@15911
  1377
lemma setsum_cl_ivl_Suc[simp]:
nipkow@15561
  1378
  "setsum f {m..Suc n} = (if Suc n < m then 0 else setsum f {m..n} + f(Suc n))"
nipkow@15561
  1379
by (auto simp:add_ac atLeastAtMostSuc_conv)
nipkow@15561
  1380
nipkow@15911
  1381
lemma setsum_op_ivl_Suc[simp]:
nipkow@15561
  1382
  "setsum f {m..<Suc n} = (if n < m then 0 else setsum f {m..<n} + f(n))"
nipkow@15561
  1383
by (auto simp:add_ac atLeastLessThanSuc)
nipkow@16041
  1384
(*
nipkow@15561
  1385
lemma setsum_cl_ivl_add_one_nat: "(n::nat) <= m + 1 ==>
nipkow@15561
  1386
    (\<Sum>i=n..m+1. f i) = (\<Sum>i=n..m. f i) + f(m + 1)"
nipkow@15561
  1387
by (auto simp:add_ac atLeastAtMostSuc_conv)
nipkow@16041
  1388
*)
nipkow@28068
  1389
nipkow@28068
  1390
lemma setsum_head:
nipkow@28068
  1391
  fixes n :: nat
nipkow@28068
  1392
  assumes mn: "m <= n" 
nipkow@28068
  1393
  shows "(\<Sum>x\<in>{m..n}. P x) = P m + (\<Sum>x\<in>{m<..n}. P x)" (is "?lhs = ?rhs")
nipkow@28068
  1394
proof -
nipkow@28068
  1395
  from mn
nipkow@28068
  1396
  have "{m..n} = {m} \<union> {m<..n}"
nipkow@28068
  1397
    by (auto intro: ivl_disj_un_singleton)
nipkow@28068
  1398
  hence "?lhs = (\<Sum>x\<in>{m} \<union> {m<..n}. P x)"
nipkow@28068
  1399
    by (simp add: atLeast0LessThan)
nipkow@28068
  1400
  also have "\<dots> = ?rhs" by simp
nipkow@28068
  1401
  finally show ?thesis .
nipkow@28068
  1402
qed
nipkow@28068
  1403
nipkow@28068
  1404
lemma setsum_head_Suc:
nipkow@28068
  1405
  "m \<le> n \<Longrightarrow> setsum f {m..n} = f m + setsum f {Suc m..n}"
nipkow@28068
  1406
by (simp add: setsum_head atLeastSucAtMost_greaterThanAtMost)
nipkow@28068
  1407
nipkow@28068
  1408
lemma setsum_head_upt_Suc:
nipkow@28068
  1409
  "m < n \<Longrightarrow> setsum f {m..<n} = f m + setsum f {Suc m..<n}"
huffman@30079
  1410
apply(insert setsum_head_Suc[of m "n - Suc 0" f])
nipkow@29667
  1411
apply (simp add: atLeastLessThanSuc_atLeastAtMost[symmetric] algebra_simps)
nipkow@28068
  1412
done
nipkow@28068
  1413
nipkow@31501
  1414
lemma setsum_ub_add_nat: assumes "(m::nat) \<le> n + 1"
nipkow@31501
  1415
  shows "setsum f {m..n + p} = setsum f {m..n} + setsum f {n + 1..n + p}"
nipkow@31501
  1416
proof-
nipkow@31501
  1417
  have "{m .. n+p} = {m..n} \<union> {n+1..n+p}" using `m \<le> n+1` by auto
nipkow@31501
  1418
  thus ?thesis by (auto simp: ivl_disj_int setsum_Un_disjoint
nipkow@31501
  1419
    atLeastSucAtMost_greaterThanAtMost)
nipkow@31501
  1420
qed
nipkow@28068
  1421
nipkow@15539
  1422
lemma setsum_add_nat_ivl: "\<lbrakk> m \<le> n; n \<le> p \<rbrakk> \<Longrightarrow>
nipkow@15539
  1423
  setsum f {m..<n} + setsum f {n..<p} = setsum f {m..<p::nat}"
nipkow@15539
  1424
by (simp add:setsum_Un_disjoint[symmetric] ivl_disj_int ivl_disj_un)
nipkow@15539
  1425
nipkow@15539
  1426
lemma setsum_diff_nat_ivl:
nipkow@15539
  1427
fixes f :: "nat \<Rightarrow> 'a::ab_group_add"
nipkow@15539
  1428
shows "\<lbrakk> m \<le> n; n \<le> p \<rbrakk> \<Longrightarrow>
nipkow@15539
  1429
  setsum f {m..<p} - setsum f {m..<n} = setsum f {n..<p}"
nipkow@15539
  1430
using setsum_add_nat_ivl [of m n p f,symmetric]
nipkow@15539
  1431
apply (simp add: add_ac)
nipkow@15539
  1432
done
nipkow@15539
  1433
nipkow@31505
  1434
lemma setsum_natinterval_difff:
nipkow@31505
  1435
  fixes f:: "nat \<Rightarrow> ('a::ab_group_add)"
nipkow@31505
  1436
  shows  "setsum (\<lambda>k. f k - f(k + 1)) {(m::nat) .. n} =
nipkow@31505
  1437
          (if m <= n then f m - f(n + 1) else 0)"
nipkow@31505
  1438
by (induct n, auto simp add: algebra_simps not_le le_Suc_eq)
nipkow@31505
  1439
haftmann@44008
  1440
lemma setsum_restrict_set':
haftmann@44008
  1441
  "finite A \<Longrightarrow> setsum f {x \<in> A. x \<in> B} = (\<Sum>x\<in>A. if x \<in> B then f x else 0)"
haftmann@44008
  1442
  by (simp add: setsum_restrict_set [symmetric] Int_def)
haftmann@44008
  1443
haftmann@44008
  1444
lemma setsum_restrict_set'':
haftmann@44008
  1445
  "finite A \<Longrightarrow> setsum f {x \<in> A. P x} = (\<Sum>x\<in>A. if P x  then f x else 0)"
haftmann@44008
  1446
  by (simp add: setsum_restrict_set' [of A f "{x. P x}", simplified mem_Collect_eq])
nipkow@31509
  1447
nipkow@31509
  1448
lemma setsum_setsum_restrict:
haftmann@44008
  1449
  "finite S \<Longrightarrow> finite T \<Longrightarrow>
haftmann@44008
  1450
    setsum (\<lambda>x. setsum (\<lambda>y. f x y) {y. y \<in> T \<and> R x y}) S = setsum (\<lambda>y. setsum (\<lambda>x. f x y) {x. x \<in> S \<and> R x y}) T"
haftmann@44008
  1451
  by (simp add: setsum_restrict_set'') (rule setsum_commute)
nipkow@31509
  1452
nipkow@31509
  1453
lemma setsum_image_gen: assumes fS: "finite S"
nipkow@31509
  1454
  shows "setsum g S = setsum (\<lambda>y. setsum g {x. x \<in> S \<and> f x = y}) (f ` S)"
nipkow@31509
  1455
proof-
nipkow@31509
  1456
  { fix x assume "x \<in> S" then have "{y. y\<in> f`S \<and> f x = y} = {f x}" by auto }
nipkow@31509
  1457
  hence "setsum g S = setsum (\<lambda>x. setsum (\<lambda>y. g x) {y. y\<in> f`S \<and> f x = y}) S"
nipkow@31509
  1458
    by simp
nipkow@31509
  1459
  also have "\<dots> = setsum (\<lambda>y. setsum g {x. x \<in> S \<and> f x = y}) (f ` S)"
nipkow@31509
  1460
    by (rule setsum_setsum_restrict[OF fS finite_imageI[OF fS]])
nipkow@31509
  1461
  finally show ?thesis .
nipkow@31509
  1462
qed
nipkow@31509
  1463
hoelzl@35171
  1464
lemma setsum_le_included:
haftmann@36307
  1465
  fixes f :: "'a \<Rightarrow> 'b::ordered_comm_monoid_add"
hoelzl@35171
  1466
  assumes "finite s" "finite t"
hoelzl@35171
  1467
  and "\<forall>y\<in>t. 0 \<le> g y" "(\<forall>x\<in>s. \<exists>y\<in>t. i y = x \<and> f x \<le> g y)"
hoelzl@35171
  1468
  shows "setsum f s \<le> setsum g t"
hoelzl@35171
  1469
proof -
hoelzl@35171
  1470
  have "setsum f s \<le> setsum (\<lambda>y. setsum g {x. x\<in>t \<and> i x = y}) s"
hoelzl@35171
  1471
  proof (rule setsum_mono)
hoelzl@35171
  1472
    fix y assume "y \<in> s"
hoelzl@35171
  1473
    with assms obtain z where z: "z \<in> t" "y = i z" "f y \<le> g z" by auto
hoelzl@35171
  1474
    with assms show "f y \<le> setsum g {x \<in> t. i x = y}" (is "?A y \<le> ?B y")
hoelzl@35171
  1475
      using order_trans[of "?A (i z)" "setsum g {z}" "?B (i z)", intro]
hoelzl@35171
  1476
      by (auto intro!: setsum_mono2)
hoelzl@35171
  1477
  qed
hoelzl@35171
  1478
  also have "... \<le> setsum (\<lambda>y. setsum g {x. x\<in>t \<and> i x = y}) (i ` t)"
hoelzl@35171
  1479
    using assms(2-4) by (auto intro!: setsum_mono2 setsum_nonneg)
hoelzl@35171
  1480
  also have "... \<le> setsum g t"
hoelzl@35171
  1481
    using assms by (auto simp: setsum_image_gen[symmetric])
hoelzl@35171
  1482
  finally show ?thesis .
hoelzl@35171
  1483
qed
hoelzl@35171
  1484
nipkow@31509
  1485
lemma setsum_multicount_gen:
nipkow@31509
  1486
  assumes "finite s" "finite t" "\<forall>j\<in>t. (card {i\<in>s. R i j} = k j)"
nipkow@31509
  1487
  shows "setsum (\<lambda>i. (card {j\<in>t. R i j})) s = setsum k t" (is "?l = ?r")
nipkow@31509
  1488
proof-
nipkow@31509
  1489
  have "?l = setsum (\<lambda>i. setsum (\<lambda>x.1) {j\<in>t. R i j}) s" by auto
nipkow@31509
  1490
  also have "\<dots> = ?r" unfolding setsum_setsum_restrict[OF assms(1-2)]
nipkow@31509
  1491
    using assms(3) by auto
nipkow@31509
  1492
  finally show ?thesis .
nipkow@31509
  1493
qed
nipkow@31509
  1494
nipkow@31509
  1495
lemma setsum_multicount:
nipkow@31509
  1496
  assumes "finite S" "finite T" "\<forall>j\<in>T. (card {i\<in>S. R i j} = k)"
nipkow@31509
  1497
  shows "setsum (\<lambda>i. card {j\<in>T. R i j}) S = k * card T" (is "?l = ?r")
nipkow@31509
  1498
proof-
nipkow@31509
  1499
  have "?l = setsum (\<lambda>i. k) T" by(rule setsum_multicount_gen)(auto simp:assms)
huffman@35216
  1500
  also have "\<dots> = ?r" by(simp add: mult_commute)
nipkow@31509
  1501
  finally show ?thesis by auto
nipkow@31509
  1502
qed
nipkow@31509
  1503
hoelzl@56194
  1504
lemma setsum_nat_group: "(\<Sum>m<n::nat. setsum f {m * k ..< m*k + k}) = setsum f {..< n * k}"
hoelzl@56194
  1505
  apply (subgoal_tac "k = 0 | 0 < k", auto)
hoelzl@56194
  1506
  apply (induct "n")
hoelzl@56194
  1507
  apply (simp_all add: setsum_add_nat_ivl add_commute atLeast0LessThan[symmetric])
hoelzl@56194
  1508
  done
nipkow@28068
  1509
nipkow@16733
  1510
subsection{* Shifting bounds *}
nipkow@16733
  1511
nipkow@15539
  1512
lemma setsum_shift_bounds_nat_ivl:
nipkow@15539
  1513
  "setsum f {m+k..<n+k} = setsum (%i. f(i + k)){m..<n::nat}"
nipkow@15539
  1514
by (induct "n", auto simp:atLeastLessThanSuc)
nipkow@15539
  1515
nipkow@16733
  1516
lemma setsum_shift_bounds_cl_nat_ivl:
nipkow@16733
  1517
  "setsum f {m+k..n+k} = setsum (%i. f(i + k)){m..n::nat}"
nipkow@16733
  1518
apply (insert setsum_reindex[OF inj_on_add_nat, where h=f and B = "{m..n}"])
nipkow@16733
  1519
apply (simp add:image_add_atLeastAtMost o_def)
nipkow@16733
  1520
done
nipkow@16733
  1521
nipkow@16733
  1522
corollary setsum_shift_bounds_cl_Suc_ivl:
nipkow@16733
  1523
  "setsum f {Suc m..Suc n} = setsum (%i. f(Suc i)){m..n}"
huffman@30079
  1524
by (simp add:setsum_shift_bounds_cl_nat_ivl[where k="Suc 0", simplified])
nipkow@16733
  1525
nipkow@16733
  1526
corollary setsum_shift_bounds_Suc_ivl:
nipkow@16733
  1527
  "setsum f {Suc m..<Suc n} = setsum (%i. f(Suc i)){m..<n}"
huffman@30079
  1528
by (simp add:setsum_shift_bounds_nat_ivl[where k="Suc 0", simplified])
nipkow@16733
  1529
nipkow@28068
  1530
lemma setsum_shift_lb_Suc0_0:
nipkow@28068
  1531
  "f(0::nat) = (0::nat) \<Longrightarrow> setsum f {Suc 0..k} = setsum f {0..k}"
nipkow@28068
  1532
by(simp add:setsum_head_Suc)
kleing@19106
  1533
nipkow@28068
  1534
lemma setsum_shift_lb_Suc0_0_upt:
nipkow@28068
  1535
  "f(0::nat) = 0 \<Longrightarrow> setsum f {Suc 0..<k} = setsum f {0..<k}"
nipkow@28068
  1536
apply(cases k)apply simp
nipkow@28068
  1537
apply(simp add:setsum_head_upt_Suc)
nipkow@28068
  1538
done
kleing@19022
  1539
haftmann@52380
  1540
lemma setsum_atMost_Suc_shift:
haftmann@52380
  1541
  fixes f :: "nat \<Rightarrow> 'a::comm_monoid_add"
haftmann@52380
  1542
  shows "(\<Sum>i\<le>Suc n. f i) = f 0 + (\<Sum>i\<le>n. f (Suc i))"
haftmann@52380
  1543
proof (induct n)
haftmann@52380
  1544
  case 0 show ?case by simp
haftmann@52380
  1545
next
haftmann@52380
  1546
  case (Suc n) note IH = this
haftmann@52380
  1547
  have "(\<Sum>i\<le>Suc (Suc n). f i) = (\<Sum>i\<le>Suc n. f i) + f (Suc (Suc n))"
haftmann@52380
  1548
    by (rule setsum_atMost_Suc)
haftmann@52380
  1549
  also have "(\<Sum>i\<le>Suc n. f i) = f 0 + (\<Sum>i\<le>n. f (Suc i))"
haftmann@52380
  1550
    by (rule IH)
haftmann@52380
  1551
  also have "f 0 + (\<Sum>i\<le>n. f (Suc i)) + f (Suc (Suc n)) =
haftmann@52380
  1552
             f 0 + ((\<Sum>i\<le>n. f (Suc i)) + f (Suc (Suc n)))"
haftmann@52380
  1553
    by (rule add_assoc)
haftmann@52380
  1554
  also have "(\<Sum>i\<le>n. f (Suc i)) + f (Suc (Suc n)) = (\<Sum>i\<le>Suc n. f (Suc i))"
haftmann@52380
  1555
    by (rule setsum_atMost_Suc [symmetric])
haftmann@52380
  1556
  finally show ?case .
haftmann@52380
  1557
qed
haftmann@52380
  1558
lp15@56238
  1559
lemma setsum_last_plus: fixes n::nat shows "m <= n \<Longrightarrow> (\<Sum>i = m..n. f i) = f n + (\<Sum>i = m..<n. f i)"
lp15@56238
  1560
  by (cases n) (auto simp: atLeastLessThanSuc_atLeastAtMost add_commute)
lp15@56238
  1561
lp15@56238
  1562
lemma setsum_Suc_diff:
lp15@56238
  1563
  fixes f :: "nat \<Rightarrow> 'a::ab_group_add"
lp15@56238
  1564
  assumes "m \<le> Suc n"
lp15@56238
  1565
  shows "(\<Sum>i = m..n. f(Suc i) - f i) = f (Suc n) - f m"
lp15@56238
  1566
using assms by (induct n) (auto simp: le_Suc_eq)
lp15@55718
  1567
lp15@55718
  1568
lemma nested_setsum_swap:
lp15@55718
  1569
     "(\<Sum>i = 0..n. (\<Sum>j = 0..<i. a i j)) = (\<Sum>j = 0..<n. \<Sum>i = Suc j..n. a i j)"
lp15@55718
  1570
  by (induction n) (auto simp: setsum_addf)
lp15@55718
  1571
lp15@56215
  1572
lemma nested_setsum_swap':
lp15@56215
  1573
     "(\<Sum>i\<le>n. (\<Sum>j<i. a i j)) = (\<Sum>j<n. \<Sum>i = Suc j..n. a i j)"
lp15@56215
  1574
  by (induction n) (auto simp: setsum_addf)
lp15@56215
  1575
lp15@56215
  1576
lemma setsum_zero_power [simp]:
lp15@56215
  1577
  fixes c :: "nat \<Rightarrow> 'a::division_ring"
lp15@56215
  1578
  shows "(\<Sum>i\<in>A. c i * 0^i) = (if finite A \<and> 0 \<in> A then c 0 else 0)"
lp15@56215
  1579
apply (cases "finite A")
lp15@56215
  1580
  by (induction A rule: finite_induct) auto
lp15@56215
  1581
lp15@56238
  1582
lemma setsum_zero_power' [simp]:
lp15@56238
  1583
  fixes c :: "nat \<Rightarrow> 'a::field"
lp15@56238
  1584
  shows "(\<Sum>i\<in>A. c i * 0^i / d i) = (if finite A \<and> 0 \<in> A then c 0 / d 0 else 0)"
lp15@56238
  1585
  using setsum_zero_power [of "\<lambda>i. c i / d i" A]
lp15@56238
  1586
  by auto
lp15@56238
  1587
haftmann@52380
  1588
ballarin@17149
  1589
subsection {* The formula for geometric sums *}
ballarin@17149
  1590
ballarin@17149
  1591
lemma geometric_sum:
haftmann@36307
  1592
  assumes "x \<noteq> 1"
hoelzl@56193
  1593
  shows "(\<Sum>i<n. x ^ i) = (x ^ n - 1) / (x - 1::'a::field)"
haftmann@36307
  1594
proof -
haftmann@36307
  1595
  from assms obtain y where "y = x - 1" and "y \<noteq> 0" by simp_all
hoelzl@56193
  1596
  moreover have "(\<Sum>i<n. (y + 1) ^ i) = ((y + 1) ^ n - 1) / y"
haftmann@36307
  1597
  proof (induct n)
haftmann@36307
  1598
    case 0 then show ?case by simp
haftmann@36307
  1599
  next
haftmann@36307
  1600
    case (Suc n)
wenzelm@53374
  1601
    moreover from Suc `y \<noteq> 0` have "(1 + y) ^ n = (y * inverse y) * (1 + y) ^ n" by simp 
haftmann@36350
  1602
    ultimately show ?case by (simp add: field_simps divide_inverse)
haftmann@36307
  1603
  qed
haftmann@36307
  1604
  ultimately show ?thesis by simp
haftmann@36307
  1605
qed
haftmann@36307
  1606
ballarin@17149
  1607
kleing@19469
  1608
subsection {* The formula for arithmetic sums *}
kleing@19469
  1609
huffman@47222
  1610
lemma gauss_sum:
hoelzl@56193
  1611
  "(2::'a::comm_semiring_1)*(\<Sum>i\<in>{1..n}. of_nat i) = of_nat n*((of_nat n)+1)"
kleing@19469
  1612
proof (induct n)
kleing@19469
  1613
  case 0
kleing@19469
  1614
  show ?case by simp
kleing@19469
  1615
next
kleing@19469
  1616
  case (Suc n)
huffman@47222
  1617
  then show ?case
huffman@47222
  1618
    by (simp add: algebra_simps add: one_add_one [symmetric] del: one_add_one)
huffman@47222
  1619
      (* FIXME: make numeral cancellation simprocs work for semirings *)
kleing@19469
  1620
qed
kleing@19469
  1621
kleing@19469
  1622
theorem arith_series_general:
huffman@47222
  1623
  "(2::'a::comm_semiring_1) * (\<Sum>i\<in>{..<n}. a + of_nat i * d) =
kleing@19469
  1624
  of_nat n * (a + (a + of_nat(n - 1)*d))"
kleing@19469
  1625
proof cases
kleing@19469
  1626
  assume ngt1: "n > 1"
kleing@19469
  1627
  let ?I = "\<lambda>i. of_nat i" and ?n = "of_nat n"
kleing@19469
  1628
  have
kleing@19469
  1629
    "(\<Sum>i\<in>{..<n}. a+?I i*d) =
kleing@19469
  1630
     ((\<Sum>i\<in>{..<n}. a) + (\<Sum>i\<in>{..<n}. ?I i*d))"
kleing@19469
  1631
    by (rule setsum_addf)
kleing@19469
  1632
  also from ngt1 have "\<dots> = ?n*a + (\<Sum>i\<in>{..<n}. ?I i*d)" by simp
kleing@19469
  1633
  also from ngt1 have "\<dots> = (?n*a + d*(\<Sum>i\<in>{1..<n}. ?I i))"
huffman@30079
  1634
    unfolding One_nat_def
nipkow@28068
  1635
    by (simp add: setsum_right_distrib atLeast0LessThan[symmetric] setsum_shift_lb_Suc0_0_upt mult_ac)
huffman@47222
  1636
  also have "2*\<dots> = 2*?n*a + d*2*(\<Sum>i\<in>{1..<n}. ?I i)"
huffman@47222
  1637
    by (simp add: algebra_simps)
kleing@19469
  1638
  also from ngt1 have "{1..<n} = {1..n - 1}"
nipkow@28068
  1639
    by (cases n) (auto simp: atLeastLessThanSuc_atLeastAtMost)
nipkow@28068
  1640
  also from ngt1
huffman@47222
  1641
  have "2*?n*a + d*2*(\<Sum>i\<in>{1..n - 1}. ?I i) = (2*?n*a + d*?I (n - 1)*?I n)"
huffman@30079
  1642
    by (simp only: mult_ac gauss_sum [of "n - 1"], unfold One_nat_def)
huffman@23431
  1643
       (simp add:  mult_ac trans [OF add_commute of_nat_Suc [symmetric]])
huffman@47222
  1644
  finally show ?thesis
huffman@47222
  1645
    unfolding mult_2 by (simp add: algebra_simps)
kleing@19469
  1646
next
kleing@19469
  1647
  assume "\<not>(n > 1)"
kleing@19469
  1648
  hence "n = 1 \<or> n = 0" by auto
huffman@47222
  1649
  thus ?thesis by (auto simp: mult_2)
kleing@19469
  1650
qed
kleing@19469
  1651
kleing@19469
  1652
lemma arith_series_nat:
huffman@47222
  1653
  "(2::nat) * (\<Sum>i\<in>{..<n}. a+i*d) = n * (a + (a+(n - 1)*d))"
kleing@19469
  1654
proof -
kleing@19469
  1655
  have
huffman@47222
  1656
    "2 * (\<Sum>i\<in>{..<n::nat}. a + of_nat(i)*d) =
kleing@19469
  1657
    of_nat(n) * (a + (a + of_nat(n - 1)*d))"
kleing@19469
  1658
    by (rule arith_series_general)
huffman@30079
  1659
  thus ?thesis
huffman@35216
  1660
    unfolding One_nat_def by auto
kleing@19469
  1661
qed
kleing@19469
  1662
kleing@19469
  1663
lemma arith_series_int:
huffman@47222
  1664
  "2 * (\<Sum>i\<in>{..<n}. a + int i * d) = int n * (a + (a + int(n - 1)*d))"
huffman@47222
  1665
  by (fact arith_series_general) (* FIXME: duplicate *)
paulson@15418
  1666
kleing@19022
  1667
lemma sum_diff_distrib:
kleing@19022
  1668
  fixes P::"nat\<Rightarrow>nat"
kleing@19022
  1669
  shows
kleing@19022
  1670
  "\<forall>x. Q x \<le> P x  \<Longrightarrow>
kleing@19022
  1671
  (\<Sum>x<n. P x) - (\<Sum>x<n. Q x) = (\<Sum>x<n. P x - Q x)"
kleing@19022
  1672
proof (induct n)
kleing@19022
  1673
  case 0 show ?case by simp
kleing@19022
  1674
next
kleing@19022
  1675
  case (Suc n)
kleing@19022
  1676
kleing@19022
  1677
  let ?lhs = "(\<Sum>x<n. P x) - (\<Sum>x<n. Q x)"
kleing@19022
  1678
  let ?rhs = "\<Sum>x<n. P x - Q x"
kleing@19022
  1679
kleing@19022
  1680
  from Suc have "?lhs = ?rhs" by simp
kleing@19022
  1681
  moreover
kleing@19022
  1682
  from Suc have "?lhs + P n - Q n = ?rhs + (P n - Q n)" by simp
kleing@19022
  1683
  moreover
kleing@19022
  1684
  from Suc have
kleing@19022
  1685
    "(\<Sum>x<n. P x) + P n - ((\<Sum>x<n. Q x) + Q n) = ?rhs + (P n - Q n)"
kleing@19022
  1686
    by (subst diff_diff_left[symmetric],
kleing@19022
  1687
        subst diff_add_assoc2)
kleing@19022
  1688
       (auto simp: diff_add_assoc2 intro: setsum_mono)
kleing@19022
  1689
  ultimately
kleing@19022
  1690
  show ?case by simp
kleing@19022
  1691
qed
kleing@19022
  1692
lp15@55718
  1693
lemma nat_diff_setsum_reindex:
lp15@55718
  1694
  fixes x :: "'a::{comm_ring,monoid_mult}"
hoelzl@56193
  1695
  shows "(\<Sum>i<n. f (n - Suc i)) = (\<Sum>i<n. f i)"
hoelzl@56193
  1696
apply (subst setsum_reindex_cong [of "%i. n - Suc i" "{..< n}"])
lp15@55718
  1697
apply (auto simp: inj_on_def)
lp15@55718
  1698
apply (rule_tac x="n - Suc x" in image_eqI, auto)
lp15@55718
  1699
done
lp15@55718
  1700
paulson@29960
  1701
subsection {* Products indexed over intervals *}
paulson@29960
  1702
paulson@29960
  1703
syntax
paulson@29960
  1704
  "_from_to_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(PROD _ = _.._./ _)" [0,0,0,10] 10)
paulson@29960
  1705
  "_from_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(PROD _ = _..<_./ _)" [0,0,0,10] 10)
paulson@29960
  1706
  "_upt_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(PROD _<_./ _)" [0,0,10] 10)
paulson@29960
  1707
  "_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(PROD _<=_./ _)" [0,0,10] 10)
paulson@29960
  1708
syntax (xsymbols)
paulson@29960
  1709
  "_from_to_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_ = _.._./ _)" [0,0,0,10] 10)
paulson@29960
  1710
  "_from_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_ = _..<_./ _)" [0,0,0,10] 10)
paulson@29960
  1711
  "_upt_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_<_./ _)" [0,0,10] 10)
paulson@29960
  1712
  "_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_\<le>_./ _)" [0,0,10] 10)
paulson@29960
  1713
syntax (HTML output)
paulson@29960
  1714
  "_from_to_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_ = _.._./ _)" [0,0,0,10] 10)
paulson@29960
  1715
  "_from_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_ = _..<_./ _)" [0,0,0,10] 10)
paulson@29960
  1716
  "_upt_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_<_./ _)" [0,0,10] 10)
paulson@29960
  1717
  "_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Prod>_\<le>_./ _)" [0,0,10] 10)
paulson@29960
  1718
syntax (latex_prod output)
paulson@29960
  1719
  "_from_to_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
paulson@29960
  1720
 ("(3\<^raw:$\prod_{>_ = _\<^raw:}^{>_\<^raw:}$> _)" [0,0,0,10] 10)
paulson@29960
  1721
  "_from_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
paulson@29960
  1722
 ("(3\<^raw:$\prod_{>_ = _\<^raw:}^{<>_\<^raw:}$> _)" [0,0,0,10] 10)
paulson@29960
  1723
  "_upt_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
paulson@29960
  1724
 ("(3\<^raw:$\prod_{>_ < _\<^raw:}$> _)" [0,0,10] 10)
paulson@29960
  1725
  "_upto_setprod" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
paulson@29960
  1726
 ("(3\<^raw:$\prod_{>_ \<le> _\<^raw:}$> _)" [0,0,10] 10)
paulson@29960
  1727
paulson@29960
  1728
translations
paulson@29960
  1729
  "\<Prod>x=a..b. t" == "CONST setprod (%x. t) {a..b}"
paulson@29960
  1730
  "\<Prod>x=a..<b. t" == "CONST setprod (%x. t) {a..<b}"
paulson@29960
  1731
  "\<Prod>i\<le>n. t" == "CONST setprod (\<lambda>i. t) {..n}"
paulson@29960
  1732
  "\<Prod>i<n. t" == "CONST setprod (\<lambda>i. t) {..<n}"
paulson@29960
  1733
haftmann@33318
  1734
subsection {* Transfer setup *}
haftmann@33318
  1735
haftmann@33318
  1736
lemma transfer_nat_int_set_functions:
haftmann@33318
  1737
    "{..n} = nat ` {0..int n}"
haftmann@33318
  1738
    "{m..n} = nat ` {int m..int n}"  (* need all variants of these! *)
haftmann@33318
  1739
  apply (auto simp add: image_def)
haftmann@33318
  1740
  apply (rule_tac x = "int x" in bexI)
haftmann@33318
  1741
  apply auto
haftmann@33318
  1742
  apply (rule_tac x = "int x" in bexI)
haftmann@33318
  1743
  apply auto
haftmann@33318
  1744
  done
haftmann@33318
  1745
haftmann@33318
  1746
lemma transfer_nat_int_set_function_closures:
haftmann@33318
  1747
    "x >= 0 \<Longrightarrow> nat_set {x..y}"
haftmann@33318
  1748
  by (simp add: nat_set_def)
haftmann@33318
  1749
haftmann@35644
  1750
declare transfer_morphism_nat_int[transfer add
haftmann@33318
  1751
  return: transfer_nat_int_set_functions
haftmann@33318
  1752
    transfer_nat_int_set_function_closures
haftmann@33318
  1753
]
haftmann@33318
  1754
haftmann@33318
  1755
lemma transfer_int_nat_set_functions:
haftmann@33318
  1756
    "is_nat m \<Longrightarrow> is_nat n \<Longrightarrow> {m..n} = int ` {nat m..nat n}"
haftmann@33318
  1757
  by (simp only: is_nat_def transfer_nat_int_set_functions
haftmann@33318
  1758
    transfer_nat_int_set_function_closures
haftmann@33318
  1759
    transfer_nat_int_set_return_embed nat_0_le
haftmann@33318
  1760
    cong: transfer_nat_int_set_cong)
haftmann@33318
  1761
haftmann@33318
  1762
lemma transfer_int_nat_set_function_closures:
haftmann@33318
  1763
    "is_nat x \<Longrightarrow> nat_set {x..y}"
haftmann@33318
  1764
  by (simp only: transfer_nat_int_set_function_closures is_nat_def)
haftmann@33318
  1765
haftmann@35644
  1766
declare transfer_morphism_int_nat[transfer add
haftmann@33318
  1767
  return: transfer_int_nat_set_functions
haftmann@33318
  1768
    transfer_int_nat_set_function_closures
haftmann@33318
  1769
]
haftmann@33318
  1770
lp15@55242
  1771
lemma setprod_int_plus_eq: "setprod int {i..i+j} =  \<Prod>{int i..int (i+j)}"
lp15@55242
  1772
  by (induct j) (auto simp add: atLeastAtMostSuc_conv atLeastAtMostPlus1_int_conv)
lp15@55242
  1773
lp15@55242
  1774
lemma setprod_int_eq: "setprod int {i..j} =  \<Prod>{int i..int j}"
lp15@55242
  1775
proof (cases "i \<le> j")
lp15@55242
  1776
  case True
lp15@55242
  1777
  then show ?thesis
lp15@55242
  1778
    by (metis Nat.le_iff_add setprod_int_plus_eq)
lp15@55242
  1779
next
lp15@55242
  1780
  case False
lp15@55242
  1781
  then show ?thesis
lp15@55242
  1782
    by auto
lp15@55242
  1783
qed
lp15@55242
  1784
lp15@55718
  1785
lemma setprod_power_distrib:
lp15@55718
  1786
  fixes f :: "'a \<Rightarrow> 'b::comm_semiring_1"
lp15@55719
  1787
  shows "setprod f A ^ n = setprod (\<lambda>x. (f x)^n) A"
lp15@55719
  1788
proof (cases "finite A") 
lp15@55719
  1789
  case True then show ?thesis 
lp15@55719
  1790
    by (induct A rule: finite_induct) (auto simp add: power_mult_distrib)
lp15@55719
  1791
next
lp15@55719
  1792
  case False then show ?thesis 
lp15@55719
  1793
    by (metis setprod_infinite power_one)
lp15@55719
  1794
qed
lp15@55718
  1795
nipkow@8924
  1796
end