src/HOLCF/Lift.thy
changeset 40774 0437dbc127b3
parent 40773 6c12f5e24e34
child 40775 ed7a4eadb2f6
--- a/src/HOLCF/Lift.thy	Sat Nov 27 14:34:54 2010 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,133 +0,0 @@
-(*  Title:      HOLCF/Lift.thy
-    Author:     Olaf Mueller
-*)
-
-header {* Lifting types of class type to flat pcpo's *}
-
-theory Lift
-imports Discrete Up
-begin
-
-default_sort type
-
-pcpodef (open) 'a lift = "UNIV :: 'a discr u set"
-by simp_all
-
-lemmas inst_lift_pcpo = Abs_lift_strict [symmetric]
-
-definition
-  Def :: "'a \<Rightarrow> 'a lift" where
-  "Def x = Abs_lift (up\<cdot>(Discr x))"
-
-subsection {* Lift as a datatype *}
-
-lemma lift_induct: "\<lbrakk>P \<bottom>; \<And>x. P (Def x)\<rbrakk> \<Longrightarrow> P y"
-apply (induct y)
-apply (rule_tac p=y in upE)
-apply (simp add: Abs_lift_strict)
-apply (case_tac x)
-apply (simp add: Def_def)
-done
-
-rep_datatype "\<bottom>\<Colon>'a lift" Def
-  by (erule lift_induct) (simp_all add: Def_def Abs_lift_inject inst_lift_pcpo)
-
-lemmas lift_distinct1 = lift.distinct(1)
-lemmas lift_distinct2 = lift.distinct(2)
-lemmas Def_not_UU = lift.distinct(2)
-lemmas Def_inject = lift.inject
-
-
-text {* @{term UU} and @{term Def} *}
-
-lemma not_Undef_is_Def: "(x \<noteq> \<bottom>) = (\<exists>y. x = Def y)"
-  by (cases x) simp_all
-
-lemma lift_definedE: "\<lbrakk>x \<noteq> \<bottom>; \<And>a. x = Def a \<Longrightarrow> R\<rbrakk> \<Longrightarrow> R"
-  by (cases x) simp_all
-
-text {*
-  For @{term "x ~= UU"} in assumptions @{text defined} replaces @{text
-  x} by @{text "Def a"} in conclusion. *}
-
-method_setup defined = {*
-  Scan.succeed (fn ctxt => SIMPLE_METHOD'
-    (etac @{thm lift_definedE} THEN' asm_simp_tac (simpset_of ctxt)))
-*} ""
-
-lemma DefE: "Def x = \<bottom> \<Longrightarrow> R"
-  by simp
-
-lemma DefE2: "\<lbrakk>x = Def s; x = \<bottom>\<rbrakk> \<Longrightarrow> R"
-  by simp
-
-lemma Def_below_Def: "Def x \<sqsubseteq> Def y \<longleftrightarrow> x = y"
-by (simp add: below_lift_def Def_def Abs_lift_inverse)
-
-lemma Def_below_iff [simp]: "Def x \<sqsubseteq> y \<longleftrightarrow> Def x = y"
-by (induct y, simp, simp add: Def_below_Def)
-
-
-subsection {* Lift is flat *}
-
-instance lift :: (type) flat
-proof
-  fix x y :: "'a lift"
-  assume "x \<sqsubseteq> y" thus "x = \<bottom> \<or> x = y"
-    by (induct x) auto
-qed
-
-subsection {* Continuity of @{const lift_case} *}
-
-lemma lift_case_eq: "lift_case \<bottom> f x = fup\<cdot>(\<Lambda> y. f (undiscr y))\<cdot>(Rep_lift x)"
-apply (induct x, unfold lift.cases)
-apply (simp add: Rep_lift_strict)
-apply (simp add: Def_def Abs_lift_inverse)
-done
-
-lemma cont2cont_lift_case [simp]:
-  "\<lbrakk>\<And>y. cont (\<lambda>x. f x y); cont g\<rbrakk> \<Longrightarrow> cont (\<lambda>x. lift_case \<bottom> (f x) (g x))"
-unfolding lift_case_eq by (simp add: cont_Rep_lift [THEN cont_compose])
-
-subsection {* Further operations *}
-
-definition
-  flift1 :: "('a \<Rightarrow> 'b::pcpo) \<Rightarrow> ('a lift \<rightarrow> 'b)"  (binder "FLIFT " 10)  where
-  "flift1 = (\<lambda>f. (\<Lambda> x. lift_case \<bottom> f x))"
-
-translations
-  "\<Lambda>(XCONST Def x). t" => "CONST flift1 (\<lambda>x. t)"
-  "\<Lambda>(CONST Def x). FLIFT y. t" <= "FLIFT x y. t"
-  "\<Lambda>(CONST Def x). t" <= "FLIFT x. t"
-
-definition
-  flift2 :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a lift \<rightarrow> 'b lift)" where
-  "flift2 f = (FLIFT x. Def (f x))"
-
-lemma flift1_Def [simp]: "flift1 f\<cdot>(Def x) = (f x)"
-by (simp add: flift1_def)
-
-lemma flift2_Def [simp]: "flift2 f\<cdot>(Def x) = Def (f x)"
-by (simp add: flift2_def)
-
-lemma flift1_strict [simp]: "flift1 f\<cdot>\<bottom> = \<bottom>"
-by (simp add: flift1_def)
-
-lemma flift2_strict [simp]: "flift2 f\<cdot>\<bottom> = \<bottom>"
-by (simp add: flift2_def)
-
-lemma flift2_defined [simp]: "x \<noteq> \<bottom> \<Longrightarrow> (flift2 f)\<cdot>x \<noteq> \<bottom>"
-by (erule lift_definedE, simp)
-
-lemma flift2_bottom_iff [simp]: "(flift2 f\<cdot>x = \<bottom>) = (x = \<bottom>)"
-by (cases x, simp_all)
-
-lemma FLIFT_mono:
-  "(\<And>x. f x \<sqsubseteq> g x) \<Longrightarrow> (FLIFT x. f x) \<sqsubseteq> (FLIFT x. g x)"
-by (rule cfun_belowI, case_tac x, simp_all)
-
-lemma cont2cont_flift1 [simp, cont2cont]:
-  "\<lbrakk>\<And>y. cont (\<lambda>x. f x y)\<rbrakk> \<Longrightarrow> cont (\<lambda>x. FLIFT y. f x y)"
-by (simp add: flift1_def cont2cont_LAM)
-
-end