src/HOL/Metis_Examples/Clausification.thy
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(*  Title:      HOL/Metis_Examples/Clausification.thy
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    Author:     Jasmin Blanchette, TU Muenchen
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Example that exercises Metis's Clausifier.
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*)
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section \<open>Example that Exercises Metis's Clausifier\<close>
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theory Clausification
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imports Complex_Main
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begin
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text \<open>Definitional CNF for facts\<close>
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declare [[meson_max_clauses = 10]]
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axiomatization q :: "nat \<Rightarrow> nat \<Rightarrow> bool" where
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qax: "\<exists>b. \<forall>a. (q b a \<and> q 0 0 \<and> q 1 a \<and> q a 1) \<or> (q 0 1 \<and> q 1 0 \<and> q a b \<and> q 1 1)"
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declare [[metis_new_skolem = false]]
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lemma "\<exists>b. \<forall>a. (q b a \<or> q a b)"
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by (metis qax)
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lemma "\<exists>b. \<forall>a. (q b a \<or> q a b)"
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by (metis (full_types) qax)
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lemma "\<exists>b. \<forall>a. (q b a \<and> q 0 0 \<and> q 1 a \<and> q a 1) \<or> (q 0 1 \<and> q 1 0 \<and> q a b \<and> q 1 1)"
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by (metis qax)
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lemma "\<exists>b. \<forall>a. (q b a \<and> q 0 0 \<and> q 1 a \<and> q a 1) \<or> (q 0 1 \<and> q 1 0 \<and> q a b \<and> q 1 1)"
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by (metis (full_types) qax)
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declare [[metis_new_skolem]]
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lemma "\<exists>b. \<forall>a. (q b a \<or> q a b)"
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by (metis qax)
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lemma "\<exists>b. \<forall>a. (q b a \<or> q a b)"
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by (metis (full_types) qax)
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lemma "\<exists>b. \<forall>a. (q b a \<and> q 0 0 \<and> q 1 a \<and> q a 1) \<or> (q 0 1 \<and> q 1 0 \<and> q a b \<and> q 1 1)"
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by (metis qax)
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lemma "\<exists>b. \<forall>a. (q b a \<and> q 0 0 \<and> q 1 a \<and> q a 1) \<or> (q 0 1 \<and> q 1 0 \<and> q a b \<and> q 1 1)"
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by (metis (full_types) qax)
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declare [[meson_max_clauses = 60]]
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axiomatization r :: "nat \<Rightarrow> nat \<Rightarrow> bool" where
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rax: "(r 0 0 \<and> r 0 1 \<and> r 0 2 \<and> r 0 3) \<or>
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      (r 1 0 \<and> r 1 1 \<and> r 1 2 \<and> r 1 3) \<or>
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      (r 2 0 \<and> r 2 1 \<and> r 2 2 \<and> r 2 3) \<or>
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      (r 3 0 \<and> r 3 1 \<and> r 3 2 \<and> r 3 3)"
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declare [[metis_new_skolem = false]]
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lemma "r 0 0 \<or> r 1 1 \<or> r 2 2 \<or> r 3 3"
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by (metis rax)
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lemma "r 0 0 \<or> r 1 1 \<or> r 2 2 \<or> r 3 3"
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by (metis (full_types) rax)
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declare [[metis_new_skolem]]
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lemma "r 0 0 \<or> r 1 1 \<or> r 2 2 \<or> r 3 3"
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by (metis rax)
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lemma "r 0 0 \<or> r 1 1 \<or> r 2 2 \<or> r 3 3"
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by (metis (full_types) rax)
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lemma "(r 0 0 \<and> r 0 1 \<and> r 0 2 \<and> r 0 3) \<or>
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       (r 1 0 \<and> r 1 1 \<and> r 1 2 \<and> r 1 3) \<or>
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       (r 2 0 \<and> r 2 1 \<and> r 2 2 \<and> r 2 3) \<or>
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       (r 3 0 \<and> r 3 1 \<and> r 3 2 \<and> r 3 3)"
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by (metis rax)
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lemma "(r 0 0 \<and> r 0 1 \<and> r 0 2 \<and> r 0 3) \<or>
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       (r 1 0 \<and> r 1 1 \<and> r 1 2 \<and> r 1 3) \<or>
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       (r 2 0 \<and> r 2 1 \<and> r 2 2 \<and> r 2 3) \<or>
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       (r 3 0 \<and> r 3 1 \<and> r 3 2 \<and> r 3 3)"
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by (metis (full_types) rax)
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text \<open>Definitional CNF for goal\<close>
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axiomatization p :: "nat \<Rightarrow> nat \<Rightarrow> bool" where
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pax: "\<exists>b. \<forall>a. (p b a \<and> p 0 0 \<and> p 1 a) \<or> (p 0 1 \<and> p 1 0 \<and> p a b)"
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declare [[metis_new_skolem = false]]
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lemma "\<exists>b. \<forall>a. \<exists>x. (p b a \<or> x) \<and> (p 0 0 \<or> x) \<and> (p 1 a \<or> x) \<and>
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                   (p 0 1 \<or> \<not> x) \<and> (p 1 0 \<or> \<not> x) \<and> (p a b \<or> \<not> x)"
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by (metis pax)
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lemma "\<exists>b. \<forall>a. \<exists>x. (p b a \<or> x) \<and> (p 0 0 \<or> x) \<and> (p 1 a \<or> x) \<and>
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                   (p 0 1 \<or> \<not> x) \<and> (p 1 0 \<or> \<not> x) \<and> (p a b \<or> \<not> x)"
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by (metis (full_types) pax)
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declare [[metis_new_skolem]]
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lemma "\<exists>b. \<forall>a. \<exists>x. (p b a \<or> x) \<and> (p 0 0 \<or> x) \<and> (p 1 a \<or> x) \<and>
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                   (p 0 1 \<or> \<not> x) \<and> (p 1 0 \<or> \<not> x) \<and> (p a b \<or> \<not> x)"
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by (metis pax)
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lemma "\<exists>b. \<forall>a. \<exists>x. (p b a \<or> x) \<and> (p 0 0 \<or> x) \<and> (p 1 a \<or> x) \<and>
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                   (p 0 1 \<or> \<not> x) \<and> (p 1 0 \<or> \<not> x) \<and> (p a b \<or> \<not> x)"
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by (metis (full_types) pax)
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text \<open>New Skolemizer\<close>
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declare [[metis_new_skolem]]
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lemma
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  fixes x :: real
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  assumes fn_le: "!!n. f n \<le> x" and 1: "f \<longlonglongrightarrow> lim f"
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  shows "lim f \<le> x"
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by (metis 1 LIMSEQ_le_const2 fn_le)
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definition
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  bounded :: "'a::metric_space set \<Rightarrow> bool" where
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  "bounded S \<longleftrightarrow> (\<exists>x eee. \<forall>y\<in>S. dist x y \<le> eee)"
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lemma "bounded T \<Longrightarrow> S \<subseteq> T ==> bounded S"
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by (metis bounded_def subset_eq)
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lemma
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  assumes a: "Quotient R Abs Rep T"
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  shows "symp R"
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using a unfolding Quotient_def using sympI
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by (metis (full_types))
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lemma
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  "(\<exists>x \<in> set xs. P x) \<longleftrightarrow>
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   (\<exists>ys x zs. xs = ys @ x # zs \<and> P x \<and> (\<forall>z \<in> set zs. \<not> P z))"
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by (metis split_list_last_prop[where P = P] in_set_conv_decomp)
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lemma ex_tl: "\<exists>ys. tl ys = xs"
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using list.sel(3) by fast
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6babd86a54a4 handle case where the same Skolem name is given different types in different subgoals in the new Skolemizer (this can happen if several type-instances of the same fact are needed by Metis, cf. example in "Clausify.thy") -- the solution reintroduces old code removed in a6725f293377
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lemma "(\<exists>ys::nat list. tl ys = xs) \<and> (\<exists>bs::int list. tl bs = as)"
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by (metis ex_tl)
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end