def exec_weakf(self, envr, pm):
result = ProofResult("")
result.source = self
if len(self.args) != 2:
raise ProofError("weakf takes two arguments, found: " + str(len(self.args)))
fun, notDom = map(lambda x: self.resolveOrDont(x), self.args)
if not isinstance(fun, expSemantics.FunOK):
raise ProofError("weakf expects a fun predicate, found: " + fun.shortString())
if not isinstance(notDom, judge.InTest) or notDom.nt == False:
raise ProofError("weakf expects a negative contains assertion, found: " + notDom.shortString())
if not (isinstance(notDom.rhs, expSemantics.Dom) or (isinstance(notDom.rhs, expSemantics.FunApp) and isinstance(notDom.rhs.fun, judge.DomFun))):
raise ProofError("weakf expects a domain assertion, found: " + notDom.rhs.shortString())
if isinstance(notDom.rhs, expSemantics.Dom):
domFun = notDom.rhs.arg
else:
domFun = notDom.rhs.args[0]
if domFun != fun.rhs:
raise ProofError("non-matching arguments to weakf, found: " + fun.rhs.shortString() + "; " + domFun.shortString())
if not isinstance(domFun, expSemantics.Concat) or len(domFun.elements) != 2:
raise ProofError("weakf operates on a concatenation of length two, found: " + domFun)
fType = util.isFunType(domFun.type(pm.world.symList), pm.world.symList)
if not fType:
raise ProofError("weakf expects a function, found: " + domFun.shortString())
mapping = None
qVar = envr.fresh(fType.rhs)
for c in util.atomicType(domFun.elements[0], pm.world.symList).cases:
if isinstance(c.syntax[0], symbol.List):
mapPattern = c.syntax[0].arg
ms = [symbol.IdMatch(fType.lhs[0], notDom.lhs), symbol.IdMatch(fType.rhs, qVar)]
mapping = mapPattern.substMatch(ms)
if not mapping:
raise ProofError("Could not deconstruct function: " + domFun.shortString())
df2 = expSemantics.Concat(None)
df2.elements.append(domFun.elements[0])
df2.elements.append(mapping)
df2.elements.append(domFun.elements[1])
df2.typeF = domFun.typeF
fun2 = expSemantics.FunOK(None)
fun2.rhs = df2
forall = expSemantics.Forall(None)
forall.qVars = [qVar]
forall.rhs = fun2
self.results = [forall]
result.verbose = pm.getIndent() + "weakening: " + self.results[0].shortString()
return result
def exec_fun(self, envr, pm):
result = ProofResult("")
result.source = self
if len(self.args) != 2:
raise ProofError("fun takes two arguments, found: " + str(len(self.args)))
inMap, funok = map(lambda x: self.resolveOrDont(x), self.args)
if not isinstance(inMap, judge.InTest) or inMap.nt:
raise ProofError("fun expects a positive contains assertion, found: " + inMap.shortString())
if not isinstance(funok, expSemantics.FunOK):
raise ProofError("fun expects a function predicate, found: " + funok.shortString())
if funok.rhs != inMap.rhs:
raise ProofError("mismatch of arguments to fun, found: " + inMap.rhs.shortString() + "; " + funok.rhs.shortString())
#extract the parts of the mapping
sym = util.atomicType(inMap.lhs, pm.world.symList)
fType = util.isFunType(sym, pm.world.symList)
l = r = None
if not fType:
raise ProofError("Can not construct function: " + sym.shortString())
for c in sym.cases:
if len(c.syntax) == 1 and isinstance(c.syntax[0], symbol.List):
m = inMap.lhs.isSuperType(c.syntax[0].arg, pm.world.symList)
l = m.match(fType.lhs[0])
r = m.match(fType.rhs)
if not l:
raise ProofError("Can not construct function: " + sym.shortString())
apply = expSemantics.FunApp(None)
apply.fun = funok.rhs
apply.args = [l]
eq = judge.Equality(None)
eq.nt = False
eq.lhs = apply
eq.rhs = r
self.results = [eq]
result.verbose = pm.getIndent() + "function introduction: " + eq.shortString()
return result
