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