def test_aima_example(self):
self._test_transformer(
"B11 <=> (P12 OR P21)",
AndTerm(
OrTerm(NotTerm(SymbolTerm("B11")),
OrTerm(SymbolTerm("P12"), SymbolTerm("P21"))),
AndTerm(OrTerm(NotTerm(SymbolTerm("P12")), SymbolTerm("B11")),
OrTerm(NotTerm(SymbolTerm("P21")),
SymbolTerm("B11")))))
def test_aima_example(self):
parser = PLParser()
sentence = parser.parse("B11 <=> (P12 OR P21)")
transformer = CNFTransformer()
cnf = transformer.transform(sentence)
self._test_gatherer(cnf, [
OrTerm(NotTerm(SymbolTerm("B11")),
OrTerm(SymbolTerm("P12"), SymbolTerm("P21"))),
OrTerm(NotTerm(SymbolTerm("P12")), SymbolTerm("B11")),
OrTerm(NotTerm(SymbolTerm("P21")), SymbolTerm("B11"))
])
def _transform_implication(self, term):
first_child = NotTerm(term.children[0])
second_child = term.children[1]
# Implication transformation; A => B == (NOT A) OR B
return self.transform(OrTerm(self.transform(first_child),
second_child))
def _transform_not_expression(self, term):
not_child = term.children[0]
# Check if we can remove double NOT
if not_child.type == TokenTypes.NOT:
return self.transform(not_child.children[0])
# De Morgan rule NOT (A OR B) == (NOT A) AND (NOT B)
elif not_child.type == TokenTypes.OR:
return AndTerm(self.transform(NotTerm(not_child.children[0])),
self.transform(NotTerm(not_child.children[1])))
# De Morgan rule NOT (A AND B) == (NOT A) OR (NOT B)
elif not_child.type == TokenTypes.AND:
return self.transform(
OrTerm(self.transform(NotTerm(not_child.children[0])),
self.transform(NotTerm(not_child.children[1]))))
# No rules, just return NOT expression
return term
def test_dpll1(self):
kb = KnowledgeBase()
kb.tell_str("(B12 <=> (P11 OR (P13 OR (P22 OR P02))))")
kb.tell_str("(B21 <=> (P20 OR (P22 OR (P31 OR P11))))")
kb.tell_str("(B01 <=> (P00 OR (P02 OR P11)))")
kb.tell_str("(B10 <=> (P11 OR (P20 OR P00)))")
kb.tell_str("(NOT B21)")
kb.tell_str("(NOT B12)")
kb.tell_str("(B10)")
kb.tell_str("(B01)")
kb.ask_with_dpll(SymbolTerm("P00"))
kb.ask_with_dpll(NotTerm(SymbolTerm("P00")))
def _pl_resolve(self, ci, cj):
or_gatherer = CNFOrGatherer()
(ci_symbols, ci_not_symbols) = or_gatherer.collect(ci)
(cj_symbols, cj_not_symbols) = or_gatherer.collect(cj)
symbols = cj_symbols | ci_symbols
not_symbols = cj_not_symbols | ci_not_symbols
unique_symbols = symbols - not_symbols
unique_not_symbols = not_symbols - symbols
not_symbols_set = {
NotTerm(not_symbol)
for not_symbol in unique_not_symbols
}
return create_symbols_connection(
OrTerm, list(unique_symbols | not_symbols_set), EmptyClause())
def test_as_sentence(self):
kb = KnowledgeBase()
kb.tell_str("A")
kb.tell_str("A OR B")
kb.tell_str("C <=> D")
kb.tell_str("E => NOT F")
sentence = kb.as_sentence()
expected_sentence = AndTerm(
SymbolTerm("A"),
AndTerm(
OrTerm(SymbolTerm("A"), SymbolTerm("B")),
AndTerm(
BiconditionalTerm(SymbolTerm("C"), SymbolTerm("D")),
ImplicationTerm(SymbolTerm("E"),
NotTerm(SymbolTerm("F"))))))
self.assertEqual(expected_sentence, sentence)
def test_triple_negatiation_transformation(self):
self._test_transformer("NOT (NOT (NOT A))", NotTerm(SymbolTerm("A")))
def _create_resolution_sentence(self, knowledge_base, alpha):
kb_sentence = knowledge_base.as_sentence()
return AndTerm(kb_sentence, NotTerm(alpha))
def test_not(self):
self._test_parser("NOT Java", NotTerm(SymbolTerm("Java")))
def test_not_sentence(self):
self._test_gatherer_str("NOT A", [NotTerm(SymbolTerm("A"))])
def test_complex_not(self):
self._test_parser(
"(Java AND NOT C) => Scala",
ImplicationTerm(
AndTerm(SymbolTerm("Java"), NotTerm(SymbolTerm("C"))),
SymbolTerm("Scala")))
def test_root_and_term(self):
self._test_transformer(
"((A => B) AND C)",
AndTerm(OrTerm(NotTerm(SymbolTerm("A")), SymbolTerm("B")),
SymbolTerm("C")))
def test_de_morgan2(self):
self._test_transformer(
"NOT (A OR B)",
AndTerm(NotTerm(SymbolTerm("A")), NotTerm(SymbolTerm("B"))))
def test_parsing(self):
self._test_parser(
"(B11 => (NOT P11)) AND B11",
AndTerm(
ImplicationTerm(SymbolTerm("B11"), NotTerm(SymbolTerm("P11"))),
SymbolTerm("B11")))
def test_biconditional_transformation(self):
self._test_transformer(
"A <=> B",
AndTerm(OrTerm(NotTerm(SymbolTerm("A")), SymbolTerm("B")),
OrTerm(NotTerm(SymbolTerm("B")), SymbolTerm("A"))))
def test_implication_transfromation(self):
self._test_transformer(
"A => B", OrTerm(NotTerm(SymbolTerm("A")), SymbolTerm("B")))
def test_de_morgan1(self):
self._test_transformer(
"NOT (A AND B)",
OrTerm(NotTerm(SymbolTerm("A")), NotTerm(SymbolTerm("B"))))
def test_not_parenth(self):
self._test_parser("(NOT A)", NotTerm(SymbolTerm("A")))
