author | haftmann |
Tue, 23 Feb 2010 10:11:15 +0100 | |
changeset 35316 | 870dfea4f9c0 |
parent 16733 | 236dfafbeb63 |
child 42154 | 478bdcea240a |
permissions | -rw-r--r-- |
13857 | 1 |
(* Title: HOL/Hoare/ExamplesAbort.thy |
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Author: Tobias Nipkow |
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Copyright 1998 TUM |
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Some small examples for programs that may abort. |
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*) |
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dropped axclass; dropped Id; session theory Hoare.thy
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theory ExamplesAbort imports Hoare_Logic_Abort begin |
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lemma "VARS x y z::nat |
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{y = z & z \<noteq> 0} z \<noteq> 0 \<rightarrow> x := y div z {x = 1}" |
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by vcg_simp |
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lemma |
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"VARS a i j |
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{k <= length a & i < k & j < k} j < length a \<rightarrow> a[i] := a!j {True}" |
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apply vcg_simp |
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done |
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lemma "VARS (a::int list) i |
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{True} |
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i := 0; |
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WHILE i < length a |
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INV {i <= length a} |
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DO a[i] := 7; i := i+1 OD |
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{True}" |
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apply vcg_simp |
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done |
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end |