// "invariant-04.hac"
// copy-modified from "invariant-03.hac"
// testing basic invariant expressions
 
defproc foo(bool x, y) {
spec {
	$(x | y)
	// synonymous with excllo(x, y)
}
prs {
	x	=> y-
}
}

defproc bar(bool w, z) {
prs {
	w	=> z-
}
spec {
	$(~(w & z))	// exclhi
}
}

bool a, b;
foo fubar(a, b);
bar barfu(b, a);

