def process_prospectives(self):
print("\nProcessing prospectives")
for nv, (action, cond) in self.nexinfer.items():
print("\tprocessing %s in %s" % (nv, action))
action_suffix = self.action2suffix[action]
action_nvars = And(action_suffix).get_free_variables()
action_nvars = action_nvars.intersection(
self.system._nex2pre.keys())
action_pvars = set()
for n in action_nvars:
action_pvars.add(self.system._nex2pre[n])
action_prefix = self.action2prefix[action]
concs_global = []
concs = []
for c in action_prefix:
cvars = c.get_free_variables()
common = cvars.intersection(action_pvars)
if len(common) == 0:
statevars = cvars.intersection(self.system._states)
statevars = statevars.difference(self.system._globals)
if len(statevars) == 0:
concs_global.append(c)
else:
concs.append(c)
if (len(concs) + len(concs_global)) == 0:
print("\t\tskipping %s since no static precondition found" %
nv)
continue
qvars = set()
if cond.is_forall():
cqvars = cond.quantifier_vars()
for v in cqvars:
qvars.add(v)
cond = cond.arg(0)
if not (cond.is_iff() or cond.is_equals()):
continue
lhs = cond.arg(0)
rhs = cond.arg(1)
lvars = lhs.get_free_variables()
rvars = rhs.get_free_variables()
if nv in rvars:
lhs, rhs = rhs, lhs
lvars, rvars = rvars, lvars
if nv in rvars:
continue
ldvars = lvars.difference(qvars)
if len(ldvars) != 1:
continue
ldvar = next(iter(ldvars))
if nv != ldvar:
continue
if len(qvars) != 0:
if not lhs.is_function_application():
continue
nsym = lhs.function_name()
if nv != nsym:
continue
if len(self.action2def) != 0:
rhs = rhs.substitute(self.action2def[action])
rconds = []
rval = self.process_assign(rhs, rconds)
premise = []
qsubs = {}
for c in rconds:
if c.is_iff() or c.is_equals():
lc = c.arg(0)
rc = c.arg(1)
if rc.is_symbol():
if rc in qvars:
lc, rc = rc, lc
if lc.is_symbol():
if lc in qvars:
if rc in self.system._others:
qsubs[rc] = lc
continue
premise.append(c)
eq = EqualsOrIff(lhs, rval)
premise.insert(0, eq)
prem = And(premise)
qsubs[nv] = self.system._nex2pre[nv]
prem = prem.substitute(qsubs)
ivars = prem.get_free_variables()
ivars = ivars.intersection(self.system._others)
if len(ivars) != 0:
for v in ivars:
vname = "Q" + str(v)
vname = vname.replace(":", "")
vnew = Symbol(vname, v.symbol_type())
qsubs[v] = vnew
qvars.add(vnew)
prem = prem.substitute(qsubs)
if len(concs_global) != 0:
concs.append(None)
for conc in concs:
if conc == None:
conc = And(concs_global)
else:
if len(concs_global) != 0:
conc = And(conc, And(concs_global))
conc = conc.substitute(qsubs)
ivars = conc.get_free_variables()
ivars = ivars.intersection(self.system._others)
evars = []
if len(ivars) != 0:
esubs = {}
for v in ivars:
vname = "Q" + str(v)
vname = vname.replace(":", "")
vnew = Symbol(vname, v.symbol_type())
esubs[v] = vnew
evars.append(vnew)
conc = conc.substitute(esubs)
# conc = Exists(evars, conc)
# evars = []
# print("evars ", evars)
# print("conc ", conc)
inference = Implies(prem, conc)
qvars2 = []
# if len(qvars) != 0:
# for u in qvars:
# ut = u.symbol_type()
# for e in evars:
# et = e.symbol_type()
# if not self.strat.allowed_arc(ut, et):
# qvars2.append(u)
uqvars = qvars.difference(qvars2)
# for u in qvars2:
# if u in qvars:
# qvars.remove(u)
# print("qvars2 ", qvars2)
# print("uqvars ", uqvars)
if len(qvars2) != 0:
inference = ForAll(qvars2, inference)
if len(evars) != 0:
inference = Exists(evars, inference)
if len(uqvars) != 0:
inference = ForAll(uqvars, inference)
iname = "syntax" + str(len(self.system._infers) + 1)
self.system._infers[inference] = iname
print("\t\tinferred %s: %s" % (iname, inference))
