| author | wenzelm | 
| Sat, 12 Mar 2022 23:21:28 +0100 | |
| changeset 75273 | f1c6e778e412 | 
| parent 67399 | eab6ce8368fa | 
| permissions | -rw-r--r-- | 
| 42151 | 1  | 
(* Title: HOL/HOLCF/Discrete.thy  | 
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2841
 
c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
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Author: Tobias Nipkow  | 
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c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
 | 
3  | 
*)  | 
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c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
 | 
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section \<open>Discrete cpo types\<close>  | 
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theory Discrete  | 
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imports Cont  | 
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begin  | 
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datatype 'a discr = Discr "'a :: type"  | 
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subsection \<open>Discrete cpo class instance\<close>  | 
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added subsection headings, cleaned up some proofs
 
huffman 
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instantiation discr :: (type) discrete_cpo  | 
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begin  | 
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definition "((\<sqsubseteq>) :: 'a discr \<Rightarrow> 'a discr \<Rightarrow> bool) = (=)"  | 
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instance  | 
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by standard (simp add: below_discr_def)  | 
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end  | 
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subsection \<open>\emph{undiscr}\<close>
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2841
 
c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
 | 
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definition undiscr :: "('a::type)discr \<Rightarrow> 'a"
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where "undiscr x = (case x of Discr y \<Rightarrow> y)"  | 
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2841
 
c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
 | 
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lemma undiscr_Discr [simp]: "undiscr (Discr x) = x"  | 
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by (simp add: undiscr_def)  | 
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lemma Discr_undiscr [simp]: "Discr (undiscr y) = y"  | 
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by (induct y) simp  | 
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2841
 
c2508f4ab739
Added "discrete" CPOs and modified IMP to use those rather than "lift"
 
nipkow 
parents:  
diff
changeset
 | 
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end  |