def query(
self,
literal: Literal,
mode: RuleType = RuleType.DEFEASIBLE
) -> Tuple[Answer, Optional[Warrant]]:
if self._answers is None:
self._answers = {}
answers = self._answers.setdefault(mode, {})
if literal not in answers:
if literal not in self.get_literals(mode):
answers.setdefault(literal, (Answer.UNKNOWN, None))
else:
warrant = self._get_warrant(literal, mode)
if warrant is not None:
answers.setdefault(literal, (Answer.YES, warrant))
else:
complement = literal.get_complement()
warrant = self._get_warrant(complement, mode)
if warrant is not None:
answers.setdefault(literal, (Answer.NO, warrant))
else:
answers.setdefault(literal, (Answer.UNDECIDED, None))
return self._answers.get(mode, {}).get(literal, (Answer.UNKNOWN, None))
def disagree(literal1: Literal, literal2: Literal,
rules: Iterable[Rule]) -> bool:
if literal1.get_complement() == literal2:
return True
index = as_index(rules, RuleType.STRICT)
index.setdefault(literal1, set()).add(literal1.as_fact())
index.setdefault(literal2, set()).add(literal2.as_fact())
return bool(is_contradictory(index))