def emission(self):
"""Sending a message must be preceded by observation of its ins,
but cannot be preceded by observation of any nils or outs"""
s = partial(observe, self.sender)
ins = [impl(self.sent, sequential(s(p), self.sent))
for p in self.ins]
nils = [impl(and_(self.sent, s(p)), sequential(self.sent, s(p)))
for p in self.nils]
outs = [impl(self.sent, simultaneous(s(p), self.sent))
for p in self.outs]
return and_(*(ins + nils + outs))
def reception(self):
"Each message reception is accompanied by the observation of its parameters; either they are observed, or the message itself is not"
clauses = [impl(self.received,
or_(sequential(p, self.received),
simultaneous(p, self.received)))
for p in map(partial(observe, self.recipient), self.ins | self.outs)]
return and_(*clauses)
def blocked(self):
s = partial(observe, self.sender)
ins = [~s(p) for p in self.ins]
nils = [and_(s(p), ~(sequential(s(p), self.sent) |
simultaneous(s(p), self.sent))) for p in self.nils]
outs = [s(p) for p in self.outs]
return or_(*(nils + outs + ins))
def _complete(self):
"Each out parameter must be observed by at least one role"
clauses = []
for p in self.outs:
clauses.append(or_(*[m.received for m in self.p_cover(p)
if m.parameters[p].adornment is 'out']))
return and_(*clauses)
def maximal(self):
"Each message must be sent, or it must be blocked by a prior binding"
clauses = []
for m in self.messages.values():
clauses.append(m.sent | m.blocked)
return and_(*clauses)
def _enactable(self):
"Some message must be received containing each parameter"
clauses = []
for p in self.public_parameters:
clauses.append(or_(*[m.received for m in self.p_cover(p)]))
return and_(*clauses)