зеркало из https://github.com/microsoft/ivy.git
39 строки
682 B
XML
39 строки
682 B
XML
#lang ivy1.7
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type client
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type server
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relation link(X:client, Y:server)
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relation semaphore(X:server)
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after init {
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semaphore(W) := true;
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link(X,Y) := false
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}
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action connect(x:client,y:server) = {
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assume semaphore(y);
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link(x,y) := true;
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semaphore(y) := false
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}
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action disconnect(x:client,y:server) = {
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assume link(x,y);
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link(x,y) := false;
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semaphore(y) := true
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}
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var x:client
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var y:server
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var z:client
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invariant [safety] ~(x ~= z & link(x,y) & link(z,y))
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axiom x = X & z = X -> x = z
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axiom y = Y -> (semaphore(y) = semaphore(Y))
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axiom x = X & y = Y -> (link(x,y) = link(X,Y))
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axiom z = X & y = Y -> (link(z,y) = link(X,Y))
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export connect
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export disconnect
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