def test_valid_valuation_satisfies(self):
variable = Variable('a')
mapping = {variable: True}
v = Valuation(mapping)
c = Clause([Literal(variable)])
self.assertTrue(c.is_satisfied(v))
def __init__(self):
self.clauses = []
self.truth_assignment = []
self.truth_values = []
for x in range(300):
#for x in range(18):
self.clauses.append(Clause())
def test_invalid_valuation_does_not_satisfy(self):
variable = Variable('a')
v = Valuation({variable: False})
c = Clause([Literal(variable)])
self.assertFalse(c.is_satisfied(v))
def test_is_satisfied_with_invalid_argument_type_fails(self):
c = Clause([Literal(Variable('a'))])
self.assertRaises(TypeError, lambda l: c.is_satisfied({}))
def run_dpll(formula_so_far, truth_so_far):
# begin dpll by calling unit prop
new_formula, new_assignment = unit_propagation(formula_so_far[:], truth_so_far[:])
print(new_formula)
print(new_assignment)
# satisfiable instance
if len(new_formula) == 0:
# end timer for individual run
end = time.time()
# go to next sat instance
return True
# # unsatisfiable instance
# if len(new_formula) > 0:
#
# # end timer for individual run
# end = time.time()
#
# # add totals and running times to arrays
# totals.append(1)
# running_times.append((end - start))
#
# # go to next sat instance
# return False
# find first variable unassigned in new_assignment
first_unassigned_literal = 0
for q in range(len(new_assignment)):
if new_assignment[q] is None:
first_unassigned_literal = q + 1
break
# create unit clause and add to formula
unit_clause = Clause()
unit_clause.create_unit_clause(first_unassigned_literal)
new_formula.insert(0, unit_clause)
# add to truth assignment
new_assignment[first_unassigned_literal - 1] = True
new_assignment[first_unassigned_literal + 99] = False
# # add to truth assignment
# if first_unassigned_literal <= 100:
# new_assignment[first_unassigned_literal-1] = True
# new_assignment[first_unassigned_literal+99] = False
# else:
# new_assignment[first_unassigned_literal-1] = False
# new_assignment[first_unassigned_literal-101] = True
print(new_assignment)
print(new_formula)
# recursively run dpll
result = run_dpll(new_formula[:], new_assignment[:])
if result:
return True
else:
# create unit clause and add to formula
unit_clause = Clause()
unit_clause.create_unit_clause(first_unassigned_literal + 100)
new_formula.insert(0, unit_clause)
# add to truth assignment
new_assignment[first_unassigned_literal - 1] = False
new_assignment[first_unassigned_literal + 99] = True
return run_dpll(new_formula[:], new_assignment[:])
