def test_is_cnf():
x, y, z = symbols('x,y,z')
assert is_cnf(x) is True
assert is_cnf(x | y | z) is True
assert is_cnf(x & y & z) is True
assert is_cnf((x | y) & z) is True
assert is_cnf((x & y) | z) is False
def test_is_cnf():
x, y, z = symbols('x,y,z')
assert is_cnf(x) is True
assert is_cnf(x | y | z) is True
assert is_cnf(x & y & z) is True
assert is_cnf((x | y) & z) is True
assert is_cnf((x & y) | z) is False
def expr_to_satfmt(expr, mapper, convert_cnf=True):
"""
Takes a sympy formula in CNF, return a list of lists of integers for
use with pycosat
"""
# ensure CNF
cnf_expr = None
if convert_cnf and not is_cnf(expr):
print(
"Got a non-CNF expression, converting... (depending on the size and "
"structure of the expression, this could take a prohibitively long time)"
)
# see https://cs.stackexchange.com/a/41071/97082 for an explanation
# if this becomes a problem, Tseitin transforms might be worth exploring
# for now I'm just gonna try to stick to CNF everywhere
cnf_expr = to_cnf(expr, simplify=True, force=True)
else:
cnf_expr = expr
# make list of lists of integers
clauses = []
for clause in cnf_expr.args:
if type(clause) in [Symbol, Not]:
clauses.append([mapper.to_int(clause)])
else:
clauses.append(list(map(mapper.to_int, clause.args)))
return clauses
def addToKnowledgeBase(self, box):
expression_box_neighbours = S.false
neighbours = self.getNeighbours(box)
if box.clue == 0:
for neighbour in neighbours:
if neighbour in self.fringe:
self.fringe.remove(neighbour)
# neighbour.solved = True
# self.solvedBoxes += 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.symbol: False})
if (neighbour.solved == False):
self.observedMineField[neighbour.row][
neighbour.col].prob = 0.0
self.fringe.append(neighbour)
elif box.clue == 8:
for neighbour in neighbours:
if neighbour in self.fringe:
self.fringe.remove(neighbour)
neighbour.solved = True
neighbour.mineFlag = IS_MINE
self.solvedBoxes += 1
# self.unseenBoxes -= 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.symbol: True})
self.observedMineField[neighbour.row][neighbour.col].prob = 1.0
else:
for ci in range(0, box.clue + 1):
for subset in itertools.combinations(neighbours, box.clue):
expression_subset = S.true
for neighbour in neighbours:
if neighbour not in subset:
expression_subset = expression_subset & ~neighbour.symbol
else:
expression_subset = expression_subset & neighbour.symbol
expression_box_neighbours = expression_box_neighbours | (
expression_subset)
for neighbour in neighbours:
if neighbour.solved == True:
if neighbour.mineFlag:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.symbol: True})
else:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.symbol: False})
# print("Expression Generated:", expression_box_neighbours)
expr = expression_box_neighbours
if not is_cnf(expr):
expr = to_cnf(expr, simplify=True)
# print("Converted new expression")
# print("After CNF:", expr)
self.updateKnowledgeBase(expr, box)
def addInfoToKnowledgeBase(self, box):
expression_box_neighbours = S.false
neighbours = self.getNeighbours(box)
if box.clue == 0:
for neighbour in neighbours:
if neighbour in self.fringe:
self.fringe.remove(neighbour)
# neighbour.solved = True
# self.solvedBoxes += 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.denotation: False})
if (neighbour.solved == False):
self.agentObservedMineField[neighbour.row][
neighbour.col].prob = 0.0
self.fringe.append(neighbour)
elif box.clue == 8:
for neighbour in neighbours:
if neighbour in self.fringe:
self.fringe.remove(neighbour)
neighbour.solved = True
neighbour.mineFlag = IS_MINE
self.solvedBoxes += 1
# self.unseenBoxes -= 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.denotation: True})
self.agentObservedMineField[neighbour.row][
neighbour.col].prob = 1.0
else:
for clue_i in range(0, box.clue + 1):
for subset in itertools.combinations(neighbours, box.clue):
expression_subset = S.true
for neighbour in neighbours:
if neighbour not in subset:
expression_subset = expression_subset & ~neighbour.denotation
else:
expression_subset = expression_subset & neighbour.denotation
expression_box_neighbours = expression_box_neighbours | (
expression_subset)
for neighbour in neighbours:
if neighbour.solved:
if neighbour.mineFlag:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.denotation: True})
else:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.denotation: False})
expression = expression_box_neighbours
if not is_cnf(expression):
expression = to_cnf(expression, simplify=True)
self.updateKnowledgeBaseInfo(expression, box)
def test_issue_18904():
x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15 = symbols('x1:16')
eq = (( x1 & x2 & x3 & x4 & x5 & x6 & x7 & x8 & x9 ) |
( x1 & x2 & x3 & x4 & x5 & x6 & x7 & x10 & x9 ) |
( x1 & x11 & x3 & x12 & x5 & x13 & x14 & x15 & x9 ))
assert is_cnf(to_cnf(eq))
raises(ValueError, lambda: to_cnf(eq, simplify=True))
for f, t in zip((And, Or), (to_cnf, to_dnf)):
eq = f(x1, x2, x3, x4, x5, x6, x7, x8, x9)
raises(ValueError, lambda: to_cnf(eq, simplify=True))
assert t(eq, simplify=True, force=True) == eq
def test_is_cnf():
assert is_cnf(x) is True
assert is_cnf(x | y | z) is True
assert is_cnf(x & y & z) is True
assert is_cnf((x | y) & z) is True
assert is_cnf((x & y) | z) is False
assert is_cnf(~(x & y) | z) is False
def test_is_cnf():
assert is_cnf(x) is True
assert is_cnf(x | y | z) is True
assert is_cnf(x & y & z) is True
assert is_cnf((x | y) & z) is True
assert is_cnf((x & y) | z) is False
assert is_cnf(~(x & y) | z) is False
def _process_expr(self):
self._num_vars = len(self._expr.binary_symbols)
self._lit_to_var = [None] + sorted(self._expr.binary_symbols, key=str)
self._var_to_lit = dict(
zip(self._lit_to_var[1:], range(1, self._num_vars + 1)))
if self._optimization or (not is_cnf(self._expr)
and not is_dnf(self._expr)):
expr = simplify_logic(self._expr)
else:
expr = self._expr
if isinstance(expr, BooleanTrue):
ast = 'const', 1
elif isinstance(expr, BooleanFalse):
ast = 'const', 0
else:
ast = get_ast(self._var_to_lit, expr)
if ast[0] == 'or':
self._nf = DNF(ast, num_vars=self._num_vars)
else:
self._nf = CNF(ast, num_vars=self._num_vars)
def add_premise(self, sentence):
"""
:param sentence: sentence to be added
:param rank: rank corresponding to sentence.
:return:
"""
if not is_cnf(sentence):
sentence = to_cnf(sentence)
premises = self.fetch_premises()
if not PL_resolution(premises, sentence):
logging.warning(
f'{sentence} introduces a contradiction in the KB.')
# return None
if sentence in premises:
logging.warning(f'{sentence} was already part of the KB.')
return sentence
premises.append(sentence)
updated_ranks = self.update_ranks_of_existing_premises(premises)
self.premises = [
(belief, rank) for belief, rank in zip(premises, updated_ranks)
] #zip updated ranks and premises and store in
return sentence
def addInfoToKnowledgeBase(self, box):
expression_box_neighbours = S.false
neighbours = self.getNeighbours(box)
# CASE 1: The clue is 0 i.e. all neighbours are 'SAFE
if box.clue == 0:
for neighbour in neighbours:
if neighbour in self.fringe:
self.fringe.remove(neighbour)
# neighbour.solved = True
# self.solvedBoxes += 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.denotation: False})
if (neighbour.solved == False):
self.agentObservedMineField[neighbour.row][
neighbour.col].prob = 0.0
self.fringe.append(neighbour)
# CASE 2: 100 percent confidence in all the neighbours being a mine
elif box.clue == 8:
for neighbour in neighbours:
if neighbour in self.fringe:
# As 'Pass by Value' is being used here
self.fringe.remove(neighbour)
neighbour.solved = True
neighbour.mineFlag = IS_MINE
self.solvedBoxes += 1
self.knowledgeBase = self.knowledgeBase.subs(
{neighbour.denotation: True})
self.agentObservedMineField[neighbour.row][
neighbour.col].prob = 1.0
# CASE 3: The clue lies between 0 and 1 (exclusive)
else:
for subset in itertools.combinations(neighbours, box.clue):
expression_subset = S.true
# Forming the expression for the neighbours of a given box
for neighbour in neighbours:
if neighbour not in subset:
expression_subset = expression_subset & ~neighbour.denotation
else:
expression_subset = expression_subset & neighbour.denotation
expression_box_neighbours = expression_box_neighbours | expression_subset
# Updating the expression obtained above
for neighbour in neighbours:
if neighbour.solved:
if neighbour.mineFlag:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.denotation: True})
else:
expression_box_neighbours = expression_box_neighbours.subs(
{neighbour.denotation: False})
# print("Expression Generated:", expression_box_neighbours)
expression = expression_box_neighbours
if not is_cnf(expression):
expression = to_cnf(expression, simplify=True)
# print("Converted new expression")
# print("After CNF:", expr)
self.updateKnowledgeBaseInfo(expression, box)
from sympy.logic.boolalg import ITE, And, Xor, Or from sympy.logic.boolalg import to_cnf, to_dnf from sympy.logic.boolalg import is_cnf, is_dnf from sympy.abc import A, B, C from sympy.abc import X, Y, Z from sympy.abc import a, b, c ITE(True, False, True) ITE(Or(True, False), And(True, True), Xor(True, True)) ITE(a, b, c) ITE(True, a, b) ITE(False, a, b) ITE(a, b, c) to_cnf(~(A | B) | C) to_cnf((A | B) & (A | ~A), True) to_dnf(Y & (X | Z)) to_dnf((X & Y) | (X & ~Y) | (Y & Z) | (~Y & Z), True) is_cnf(X | Y | Z) is_cnf(X & Y & Z) is_cnf((X & Y) | Z) is_cnf(X & (Y | Z)) is_dnf(X | Y | Z) is_dnf(X & Y & Z) is_dnf((X & Y) | Z) is_dnf(X & (Y | Z))
def test_issue_9949():
assert is_cnf(to_cnf((b > -5) | (a > 2) & (a < 4)))
from sympy.abc import A, B, D print(to_cnf(~(A | B) | D)) print(to_cnf((A | B) & (A | ~A), True)) #dnf from sympy.logic.boolalg import to_dnf from sympy.abc import A, B, C print(to_dnf(B & (A | C))) print(to_dnf((A & B) | (A & ~B) | (B & C) | (~B & C), True)) #to check cnf and dnf from sympy.logic.boolalg import is_cnf from sympy.abc import A, B, C from sympy.logic.boolalg import is_dnf from sympy.abc import A, B, C print(is_cnf(A | B | C)) print(is_cnf((A & B) | C)) print(is_dnf(A | B | C)) print(is_dnf(A & (B | C))) #simplify logic from sympy.logic import simplify_logic from sympy.abc import x, y, z from sympy import S b = (~x & ~y & ~z) | (~x & ~y & z) print(simplify_logic(b))
def test_is_cnf():
x, y, z = symbols('xyz')
assert is_cnf(x | y | z) == True
assert is_cnf(x & y & z) == True
assert is_cnf((x | y) & z) == True
assert is_cnf((x & y) | z) == False
def checkcnf():
from sympy.logic.boolalg import is_cnf
from sympy.abc import A, B, C
expr = input(("Enter a logic expression to check for CNF"))
print(is_cnf(expr))
def test_is_cnf():
x, y, z = symbols('xyz')
assert is_cnf(x | y | z) == True
assert is_cnf(x & y & z) == True
assert is_cnf((x | y) & z) == True
assert is_cnf((x & y) | z) == False