hw4

from utils import *
from logic import *
from notebook import psource

c = PropKB()

c.tell(expr('A & B'))

c.clauses

[A, B]

c.ask_if_true(expr('A <=> B'))

True

d=PropKB()

d.tell(expr('A <=> B'))

d.clauses

[(A | ~B), (B | ~A)]

d.ask_if_true(expr('A | B'))

False

e = PropKB()

e.tell(expr('A <=> B'))

e.clauses

[(A | ~B), (B | ~A)]

e.ask_if_true(expr('~A | B'))

True

f = PropKB()

f.tell(expr('(A | B) ==> C'))

f.clauses

[(~A | C), (~B | C)]

f.ask_if_true(expr('(A ==> C) | (B ==> C)'))

True

g = PropKB()

g.tell(expr('C | (~A & ~B)'))

g.clauses

[(~A | C), (~B | C)]

kb3.clauses

[(~A | A), (B | A), (~A | ~B), (B | ~B)]

g.ask_if_true(expr('(A ==> C) & (B ==> C)'))

True

h = PropKB()

h.tell(expr('(A | B) & (~C | ~D | E)'))

h.clauses

[(A | B), (~C | ~D | E)]

h.ask_if_true(expr('A | B'))

True

i = PropKB()

i.tell(expr('(A | B) & (~C | ~D | E)'))

i.clauses

[(A | B), (~C | ~D | E)]

i.ask_if_true(expr('(A | B) & (~D | E)'))

False

Unicorn Problem

ukb = PropKB()

ukb.tell(expr('Mythical ==> Immortal'))

ukb.tell(expr('~Mythical ==> (~Immortal & Mammal)'))

ukb.tell(expr('(Immortal | Mammal) ==> Horned'))

ukb.tell(expr('Horned ==> Magical'))

ukb.clauses

[(Immortal | ~Mythical),
 (~Immortal | Mythical),
 (Mammal | Mythical),
 (~Immortal | Horned),
 (~Mammal | Horned),
 (Magical | ~Horned)]

ukb.ask_if_true(expr('Mythical'))

False

ukb.ask_if_true(expr('~Mythical'))

False

ukb.ask_if_true(expr('Magical'))

True

ukb.ask_if_true(expr('Horned'))

True