def test_apply_substitution_1(self):
expression = Function.build('p(x, A)').get_child()
substitutions = [
Substitution(Variable.build('y'), Variable.build('x'))
]
expected = [Variable.build('y'), Constant.build('A')]
self.assertEqual(
expected,
MostGeneralUnifier.apply_substitution(expression, substitutions))
def test_composition_of_substitution_4(self):
first_substitution = [
Substitution(Function.build('f(x)'), Variable.build('u'))
]
second_substitution = [
Substitution(Function.build('k(f(x))'), Variable.build('y'))
]
third_substitution = [
Substitution(Function.build('k(f(x))'), Variable.build('z'))
]
fourth_substitution = [
Substitution(Function.build('h(w)'), Variable.build('x'))
]
expected = [
Substitution(Function.build('f(h(w))'), Variable.build('u')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('y')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('z')),
Substitution(Function.build('h(w)'), Variable.build('x'))
]
output = []
output = MostGeneralUnifier.apply_composition_to_substitution(
output, first_substitution)
output = MostGeneralUnifier.apply_composition_to_substitution(
output, second_substitution)
output = MostGeneralUnifier.apply_composition_to_substitution(
output, third_substitution)
output = MostGeneralUnifier.apply_composition_to_substitution(
output, fourth_substitution)
self.assertEqual(expected, output)
def test_unification_1(self):
expression1 = Function.build('p(f(x), y, g(y ,x))')
expression2 = Function.build('p(u, k(u), g(z, h(w)))')
_, unification_substitution = MostGeneralUnifier.unify(
expression1, expression2)
expected_substitutions = [
Substitution(Function.build('f(h(w))'), Variable.build('u')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('y')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('z')),
Substitution(Function.build('h(w)'), Variable.build('x'))
]
self.assertEqual(expected_substitutions, unification_substitution)
def test_composition_of_substitution_1(self):
empty_substitution = []
first_substitution = [
Substitution(Function.build('f(y)'), Variable.build('x')),
Substitution(Variable.build('z'), Variable.build('y'))
]
self.assertEqual(
first_substitution,
MostGeneralUnifier.apply_composition_to_substitution(
empty_substitution, first_substitution))
self.assertEqual(
first_substitution,
MostGeneralUnifier.apply_composition_to_substitution(
first_substitution, empty_substitution))
def test_apply_substitution_2(self):
expression1 = Function.build('p(f(x), y, g(y ,x))').get_child()
expression2 = Function.build('p(u, k(u), g(z, h(w)))').get_child()
substitutions = [
Substitution(Function.build('f(h(w))'), Variable.build('u')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('y')),
Substitution(Function.build('k(f(h(w)))'), Variable.build('z')),
Substitution(Function.build('h(w)'), Variable.build('x'))
]
expected = Function.build(
'p(f(h(w)), k(f(h(w))), g(k(f(h(w))), h(w)))').get_child()
self.assertEqual(
expected,
MostGeneralUnifier.apply_substitution(expression1, substitutions))
self.assertEqual(
expected,
MostGeneralUnifier.apply_substitution(expression2, substitutions))
def test_unification_4(self):
expression1 = Function.build('p(f(x), Y, g(y ,x))').get_child()
expression2 = Variable.build('abc')
result, unification_substitution = MostGeneralUnifier.unify(
expression1, expression2)
self.assertFalse(result)
self.assertIsNone(unification_substitution)
def test_composition_of_substitution_3(self):
first_substitution = [
Substitution(Function.build('g(x, y)'), Variable.build('z'))
]
second_substitution = [
Substitution(Constant.build('A'), Variable.build('x')),
Substitution(Constant.build('B'), Variable.build('y')),
Substitution(Variable.build('w'), Variable.build('c')),
Substitution(Constant.build('D'), Variable.build('z'))
]
expected = [
Substitution(Function.build('g(A, B)'), Variable.build('z')),
Substitution(Constant.build('A'), Variable.build('x')),
Substitution(Constant.build('B'), Variable.build('y')),
Substitution(Variable.build('w'), Variable.build('c'))
]
output = MostGeneralUnifier.apply_composition_to_substitution(
first_substitution, second_substitution)
self.assertEqual(expected, output)
def test_composition_of_substitution_2(self):
first_substitution = [
Substitution(Function.build('f(y)'), Variable.build('x')),
Substitution(Variable.build('z'), Variable.build('y'))
]
second_substitution = [
Substitution(Variable.build('a'), Variable.build('x')),
Substitution(Variable.build('b'), Variable.build('y')),
Substitution(Variable.build('y'), Variable.build('z'))
]
expected = [
Substitution(Function.build('f(b)'), Variable.build('x')),
Substitution(Variable.build('y'), Variable.build('z'))
]
output = MostGeneralUnifier.apply_composition_to_substitution(
first_substitution, second_substitution)
self.assertEqual(expected, output)