--- a/src/HOL/Old_Number_Theory/IntFact.thy Tue Oct 18 07:04:08 2016 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,90 +0,0 @@
-(* Title: HOL/Old_Number_Theory/IntFact.thy
- Author: Thomas M. Rasmussen
- Copyright 2000 University of Cambridge
-*)
-
-section \<open>Factorial on integers\<close>
-
-theory IntFact
-imports IntPrimes
-begin
-
-text \<open>
- Factorial on integers and recursively defined set including all
- Integers from \<open>2\<close> up to \<open>a\<close>. Plus definition of product
- of finite set.
-
- \bigskip
-\<close>
-
-fun zfact :: "int => int"
- where "zfact n = (if n \<le> 0 then 1 else n * zfact (n - 1))"
-
-fun d22set :: "int => int set"
- where "d22set a = (if 1 < a then insert a (d22set (a - 1)) else {})"
-
-
-text \<open>
- \medskip @{term d22set} --- recursively defined set including all
- integers from \<open>2\<close> up to \<open>a\<close>
-\<close>
-
-declare d22set.simps [simp del]
-
-
-lemma d22set_induct:
- assumes "!!a. P {} a"
- and "!!a. 1 < (a::int) ==> P (d22set (a - 1)) (a - 1) ==> P (d22set a) a"
- shows "P (d22set u) u"
- apply (rule d22set.induct)
- apply (case_tac "1 < a")
- apply (rule_tac assms)
- apply (simp_all (no_asm_simp))
- apply (simp_all (no_asm_simp) add: d22set.simps assms)
- done
-
-lemma d22set_g_1 [rule_format]: "b \<in> d22set a --> 1 < b"
- apply (induct a rule: d22set_induct)
- apply simp
- apply (subst d22set.simps)
- apply auto
- done
-
-lemma d22set_le [rule_format]: "b \<in> d22set a --> b \<le> a"
- apply (induct a rule: d22set_induct)
- apply simp
- apply (subst d22set.simps)
- apply auto
- done
-
-lemma d22set_le_swap: "a < b ==> b \<notin> d22set a"
- by (auto dest: d22set_le)
-
-lemma d22set_mem: "1 < b \<Longrightarrow> b \<le> a \<Longrightarrow> b \<in> d22set a"
- apply (induct a rule: d22set.induct)
- apply auto
- apply (subst d22set.simps)
- apply (case_tac "b < a", auto)
- done
-
-lemma d22set_fin: "finite (d22set a)"
- apply (induct a rule: d22set_induct)
- prefer 2
- apply (subst d22set.simps)
- apply auto
- done
-
-
-declare zfact.simps [simp del]
-
-lemma d22set_prod_zfact: "\<Prod>(d22set a) = zfact a"
- apply (induct a rule: d22set.induct)
- apply (subst d22set.simps)
- apply (subst zfact.simps)
- apply (case_tac "1 < a")
- prefer 2
- apply (simp add: d22set.simps zfact.simps)
- apply (simp add: d22set_fin d22set_le_swap)
- done
-
-end