| author | paulson |
| Fri, 16 Jun 2000 13:39:21 +0200 | |
| changeset 9083 | b36787a56a1f |
| parent 6295 | 351b3c2b0d83 |
| child 10064 | 1a77667b21ef |
| permissions | -rw-r--r-- |
| 5252 | 1 |
(* Title: HOL/UNITY/Handshake.thy |
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ID: $Id$ |
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Author: Lawrence C Paulson, Cambridge University Computer Laboratory |
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Copyright 1998 University of Cambridge |
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Handshake Protocol |
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From Misra, "Asynchronous Compositions of Programs", Section 5.3.2 |
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*) |
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Handshake = Union + |
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record state = |
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BB :: bool |
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NF :: nat |
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NG :: nat |
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constdefs |
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(*F's program*) |
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cmdF :: "(state*state) set" |
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"cmdF == {(s,s'). s' = s (|NF:= Suc(NF s), BB:=False|) & BB s}"
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F :: "state program" |
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6295
351b3c2b0d83
removed the infernal States, eqStates, compatible, etc.
paulson
parents:
6012
diff
changeset
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"F == mk_program ({s. NF s = 0 & BB s}, {cmdF})"
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(*G's program*) |
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cmdG :: "(state*state) set" |
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"cmdG == {(s,s'). s' = s (|NG:= Suc(NG s), BB:=True|) & ~ BB s}"
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G :: "state program" |
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6295
351b3c2b0d83
removed the infernal States, eqStates, compatible, etc.
paulson
parents:
6012
diff
changeset
|
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"G == mk_program ({s. NG s = 0 & BB s}, {cmdG})"
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(*the joint invariant*) |
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invFG :: "state set" |
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"invFG == {s. NG s <= NF s & NF s <= Suc (NG s) & (BB s = (NF s = NG s))}"
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end |