def build_belief_base():
# There must be one color in each position
belief_base(red[0] + "v" + green[0] + "v" + yellow[0] + "v" + blue[0])
belief_base(red[1] + "v" + green[1] + "v" + yellow[1] + "v" + blue[1])
belief_base(red[2] + "v" + green[2] + "v" + yellow[2] + "v" + blue[2])
belief_base(red[3] + "v" + green[3] + "v" + yellow[3] + "v" + blue[3])
# There can only be one color in each position
belief_base()
def test_contraction(self):
b = belief_base()
for i in ['p', 'q', 'r']:
expand(b, i)
r = belief_base()
expand(r, 'r')
contract(b, 'p^q', 'full-meet')
self.assertEqual(b, r)
b = belief_base()
for i in ['p', 'q', '~pvr', 'r']:
expand(b, i)
r = belief_base()
for i in ['q', 'rv~p']:
expand(r, i)
contract(b, 'r', 'maxichoice')
self.assertEqual(b, r)
b = belief_base()
for i in ['p', '~pvr', 'r', 'p^q']:
expand(b, i)
r = belief_base()
expand(r, 'rv~p')
contract(b, 'r', 'partial-meet')
self.assertEqual(b, r)
b = belief_base()
for i in ['p', 'q', 'r']:
expand(b, i)
r = belief_base()
for i in ['q', 'r']:
expand(r, i)
contract(b, 'p^q', 'partial-meet')
self.assertEqual(b, r)
def test_revision(self):
b = belief_base()
for i in ['p', 'q', 'r']:
expand(b, i)
r = belief_base()
for i in ['p', 'q', 'r', 'p^q']:
expand(r, i)
revise(b, 'p^q', 'maxichoice')
self.assertEqual(b, r)
b = belief_base()
for i in ['p^q', 'r']:
expand(b, i)
r = belief_base()
for i in ['~p', 'r']:
expand(r, i)
revise(b, '~p', 'full-meet')
self.assertEqual(b, r)
def test_entails(self):
b = belief_base('p')
self.assertTrue(entails(b, 'p'))
self.assertFalse(entails(b, 'q'))
expand(b, 'q')
self.assertTrue(entails(b, 'p^q'))
expand(b, 'r')
self.assertFalse(entails(b, '(r^~p)'))
self.assertTrue(entails(
b, 'p^q^r^(~rvp)')) # raises error due to remove function
from belief_revision_engine import cnf, belief_base, entails, expand, contract, revise
b = belief_base()
for beliefs in ['p', 'q^r']:
expand(b, beliefs)
print("b is: {}".format(b))
revise(b, 'p^q')
print("after revision, b is: {}".format(b))
print("entails p? {}".format(entails(b, 'p')))
expand(b, '~p^q')
contract(b, 'p', 'full-meet')
print("after contraction, b is: {}".format(b))
print("entails p? {}".format(entails(b, 'p')))