def test_blocksworld_add_and_remove():
lang = blocksworld.generate_small_fstrips_bw_language()
model = Model(lang)
clear = lang.get_predicate('clear')
b1 = lang.get_constant('b1')
model.add(clear, b1)
model.remove(clear, b1)
assert evaluate(clear(b1), model) is False
def test_predicate_extensions():
lang = tarski.language()
pred = lang.predicate('pred', lang.Object, lang.Object)
o1 = lang.constant("o1", lang.Object)
o2 = lang.constant("o2", lang.Object)
model = Model(lang)
with pytest.raises(errors.ArityMismatch):
# This should raise an error, as the predicate is binary
model.add(pred)
with pytest.raises(ValueError):
# This should raise an error, as the predicate sort does not coincide with the sort of the parameters
model.add(pred, 1, 2)
model.add(pred, o1, o2)
assert not model.holds(pred, (o2, o1)) # Make sure the order in which the elements were added is respected!
assert model.holds(pred, (o1, o2))
with pytest.raises(KeyError):
# This should raise an error, as the tuple does not belong to the predicate's extension
model.remove(pred, o2, o1)
model.remove(pred, o1, o2)
with pytest.raises(KeyError):
# This should raise an error, as the tuple has been removed
model.remove(pred, o1, o2)