def test_to_nnf():
assert to_nnf(true) is true
assert to_nnf(false) is false
assert to_nnf(A) == A
assert (~A).to_nnf() == ~A
class Boo(BooleanFunction):
pass
pytest.raises(ValueError, lambda: to_nnf(~Boo(A)))
assert to_nnf(A | ~A | B) is true
assert to_nnf(A & ~A & B) is false
assert to_nnf(A >> B) == ~A | B
assert to_nnf(Equivalent(A, B, C)) == (~A | B) & (~B | C) & (~C | A)
assert to_nnf(A ^ B ^ C) == \
(A | B | C) & (~A | ~B | C) & (A | ~B | ~C) & (~A | B | ~C)
assert to_nnf(ITE(A, B, C)) == (~A | B) & (A | C)
assert to_nnf(Not(A | B | C)) == ~A & ~B & ~C
assert to_nnf(Not(A & B & C)) == ~A | ~B | ~C
assert to_nnf(Not(A >> B)) == A & ~B
assert to_nnf(Not(Equivalent(A, B, C))) == And(Or(A, B, C), Or(~A, ~B, ~C))
assert to_nnf(Not(A ^ B ^ C)) == \
(~A | B | C) & (A | ~B | C) & (A | B | ~C) & (~A | ~B | ~C)
assert to_nnf(Not(ITE(A, B, C))) == (~A | ~B) & (A | ~C)
assert to_nnf((A >> B) ^ (B >> A)) == (A & ~B) | (~A & B)
assert to_nnf((A >> B) ^ (B >> A), False) == \
(~A | ~B | A | B) & ((A & ~B) | (~A & B))
def test_eliminate_implications():
from diofant.abc import A, B, C, D
assert eliminate_implications(Implies(A, B, evaluate=False)) == (~A) | B
assert eliminate_implications(A >> (C >> Not(B))) == Or(
Or(Not(B), Not(C)), Not(A))
assert eliminate_implications(Equivalent(A, B, C, D)) == \
(~A | B) & (~B | C) & (~C | D) & (~D | A)
def test_is_literal():
assert is_literal(True) is True
assert is_literal(False) is True
assert is_literal(A) is True
assert is_literal(~A) is True
assert is_literal(Or(A, B)) is False
assert is_literal(Or(A, B)) is False
def test_bool_symbol():
"""Test that mixing symbols with boolean values
works as expected"""
assert And(A, True) == A
assert And(A, True, True) == A
assert And(A, False) is false
assert And(A, True, False) is false
assert Or(A, True) is true
assert Or(A, False) == A
def test_overloading():
"""Test that |, & are overloaded as expected"""
assert A & B == And(A, B)
assert A | B == Or(A, B)
assert (A & B) | C == Or(And(A, B), C)
assert A >> B == Implies(A, B)
assert A << B == Implies(B, A)
assert ~A == Not(A)
assert A ^ B == Xor(A, B)
def test_to_dnf():
assert to_dnf(true) == true
assert to_dnf((~B) & (~C)) == (~B) & (~C)
assert to_dnf(~(B | C)) == And(Not(B), Not(C))
assert to_dnf(A & (B | C)) == Or(And(A, B), And(A, C))
assert to_dnf(A >> B) == (~A) | B
assert to_dnf(A >> (B & C)) == (~A) | (B & C)
assert to_dnf(Equivalent(A, B), True) == \
Or(And(A, B), And(Not(A), Not(B)))
assert to_dnf(Equivalent(A, B & C), True) == \
Or(And(A, B, C), And(Not(A), Not(B)), And(Not(A), Not(C)))
def unit_propagate(clauses, symbol):
"""
Returns an equivalent set of clauses
If a set of clauses contains the unit clause l, the other clauses are
simplified by the application of the two following rules:
1. every clause containing l is removed
2. in every clause that contains ~l this literal is deleted
Arguments are expected to be in CNF.
>>> from diofant import symbols
>>> from diofant.abc import A, B, D
>>> from diofant.logic.algorithms.dpll import unit_propagate
>>> unit_propagate([A | B, D | ~B, B], B)
[D, B]
"""
output = []
for c in clauses:
if c.func != Or:
output.append(c)
continue
for arg in c.args:
if arg == ~symbol:
output.append(Or(*[x for x in c.args if x != ~symbol]))
break
if arg == symbol:
break
else:
output.append(c)
return output
def test_equals():
assert Not(Or(A, B)).equals( And(Not(A), Not(B)) ) is True
assert Equivalent(A, B).equals((A >> B) & (B >> A)) is True
assert ((A | ~B) & (~A | B)).equals((~A & ~B) | (A & B)) is True
assert (A >> B).equals(~A >> ~B) is False
assert (A >> (B >> A)).equals(A >> (C >> A)) is False
pytest.raises(NotImplementedError, lambda: And(A, A < B).equals(And(A, B > A)))
def test_satisfiable_all_models():
assert next(satisfiable(False, all_models=True)) is False
assert list(satisfiable((A >> ~A) & A, all_models=True)) == [False]
assert list(satisfiable(True, all_models=True)) == [{true: true}]
models = [{A: True, B: False}, {A: False, B: True}]
result = satisfiable(A ^ B, all_models=True)
models.remove(next(result))
models.remove(next(result))
pytest.raises(StopIteration, lambda: next(result))
assert not models
assert list(satisfiable(Equivalent(A, B), all_models=True)) == \
[{A: False, B: False}, {A: True, B: True}]
models = [{A: False, B: False}, {A: False, B: True}, {A: True, B: True}]
for model in satisfiable(A >> B, all_models=True):
models.remove(model)
assert not models
# This is a santiy test to check that only the required number
# of solutions are generated. The expr below has 2**100 - 1 models
# which would time out the test if all are generated at once.
sym = numbered_symbols()
X = [next(sym) for i in range(100)]
result = satisfiable(Or(*X), all_models=True)
for i in range(10):
assert next(result)
def eval(cls, *args):
# Check for situations where we can evaluate the Piecewise object.
# 1) Hit an unevaluable cond (e.g. x<1) -> keep object
# 2) Hit a true condition -> return that expr
# 3) Remove false conditions, if no conditions left -> raise ValueError
all_conds_evaled = True # Do all conds eval to a bool?
piecewise_again = False # Should we pass args to Piecewise again?
non_false_ecpairs = []
or1 = Or(*[cond for (_, cond) in args if cond != true])
for expr, cond in args:
# Check here if expr is a Piecewise and collapse if one of
# the conds in expr matches cond. This allows the collapsing
# of Piecewise((Piecewise(x,x<0),x<0)) to Piecewise((x,x<0)).
# This is important when using piecewise_fold to simplify
# multiple Piecewise instances having the same conds.
# Eventually, this code should be able to collapse Piecewise's
# having different intervals, but this will probably require
# using the new assumptions.
if isinstance(expr, Piecewise):
or2 = Or(*[c for (_, c) in expr.args if c != true])
for e, c in expr.args:
# Don't collapse if cond is "True" as this leads to
# incorrect simplifications with nested Piecewises.
if c == cond and (or1 == or2 or cond != true):
expr = e
piecewise_again = True
cond_eval = cls.__eval_cond(cond)
if cond_eval is None:
all_conds_evaled = False
elif cond_eval:
if all_conds_evaled:
return expr
if len(non_false_ecpairs) != 0:
if non_false_ecpairs[-1].cond == cond:
continue
elif non_false_ecpairs[-1].expr == expr:
newcond = Or(cond, non_false_ecpairs[-1].cond)
if isinstance(newcond, (And, Or)):
newcond = distribute_and_over_or(newcond)
non_false_ecpairs[-1] = ExprCondPair(expr, newcond)
continue
non_false_ecpairs.append(ExprCondPair(expr, cond))
if len(non_false_ecpairs) != len(args) or piecewise_again:
return cls(*non_false_ecpairs)
return
def test_to_cnf():
assert to_cnf(~(B | C)) == And(Not(B), Not(C))
assert to_cnf((A & B) | C) == And(Or(A, C), Or(B, C))
assert to_cnf(A >> B) == (~A) | B
assert to_cnf(A >> (B & C)) == (~A | B) & (~A | C)
assert to_cnf(A & (B | C) | ~A & (B | C), True) == B | C
assert to_cnf(Equivalent(A, B)) == And(Or(A, Not(B)), Or(B, Not(A)))
assert to_cnf(Equivalent(A, B & C)) == \
(~A | B) & (~A | C) & (~B | ~C | A)
assert to_cnf(Equivalent(A, B | C), True) == \
And(Or(Not(B), A), Or(Not(C), A), Or(B, C, Not(A)))
assert to_cnf(~(A | B) | C) == And(Or(Not(A), C), Or(Not(B), C))
def test_fcode_precedence():
assert fcode(And(x < y, y < x + 1), source_format="free") == \
"x < y .and. y < x + 1"
assert fcode(Or(x < y, y < x + 1), source_format="free") == \
"x < y .or. y < x + 1"
assert fcode(Xor(x < y, y < x + 1, evaluate=False),
source_format="free") == "x < y .neqv. y < x + 1"
assert fcode(Equivalent(x < y, y < x + 1), source_format="free") == \
"x < y .eqv. y < x + 1"
def test_bool_map():
"""
Test working of bool_map function.
"""
minterms = [[0, 0, 0, 1], [0, 0, 1, 1], [0, 1, 1, 1], [1, 0, 1, 1],
[1, 1, 1, 1]]
from diofant.abc import a, b, c, w, x, y, z
assert bool_map(Not(Not(a)), a) == (a, {a: a})
assert bool_map(SOPform([w, x, y, z], minterms),
POSform([w, x, y, z], minterms)) == \
(And(Or(Not(w), y), Or(Not(x), y), z), {x: x, w: w, z: z, y: y})
assert bool_map(SOPform([x, z, y], [[1, 0, 1]]),
SOPform([a, b, c], [[1, 0, 1]])) is not S.false
function1 = SOPform([x, z, y], [[1, 0, 1], [0, 0, 1]])
function2 = SOPform([a, b, c], [[1, 0, 1], [1, 0, 0]])
assert bool_map(function1, function2) == \
(function1, {y: a, z: b})
def test_is_nnf():
assert is_nnf(true) is True
assert is_nnf(A) is True
assert is_nnf(~A) is True
assert is_nnf(A & B) is True
assert is_nnf((A & B) | (~A & A) | (~B & B) | (~A & ~B), False) is True
assert is_nnf((A | B) & (~A | ~B)) is True
assert is_nnf(Not(Or(A, B))) is False
assert is_nnf(A ^ B) is False
assert is_nnf((A & B) | (~A & A) | (~B & B) | (~A & ~B), True) is False
def test_bool_as_set():
assert And(x <= 2, x >= -2).as_set() == Interval(-2, 2)
assert Or(x >= 2, x <= -2).as_set() == (Interval(-oo, -2, True) +
Interval(2, oo, False, True))
assert Not(x > 2, evaluate=False).as_set() == Interval(-oo, 2, True)
# issue sympy/sympy#10240
assert Not(And(x > 2, x < 3)).as_set() == \
Union(Interval(-oo, 2, True), Interval(3, oo, False, True))
assert true.as_set() == S.UniversalSet
assert false.as_set() == EmptySet()
def test_is_nnf():
from diofant.abc import A, B
assert is_nnf(true) is True
assert is_nnf(A) is True
assert is_nnf(~A) is True
assert is_nnf(A & B) is True
assert is_nnf((A & B) | (~A & A) | (~B & B) | (~A & ~B), False) is True
assert is_nnf((A | B) & (~A | ~B)) is True
assert is_nnf(Not(Or(A, B))) is False
assert is_nnf(A ^ B) is False
assert is_nnf((A & B) | (~A & A) | (~B & B) | (~A & ~B), True) is False
def test_all_or_nothing():
x = symbols('x', extended_real=True)
args = x >= -oo, x <= oo
v = And(*args)
if isinstance(v, And):
assert len(v.args) == len(args) - args.count(true)
else:
assert v
v = Or(*args)
if isinstance(v, Or):
assert len(v.args) == 2
else:
assert v
def test_all_or_nothing():
x = symbols('x', extended_real=True)
args = x >= -oo, x <= oo
v = And(*args)
if v.func is And:
assert len(v.args) == len(args) - args.count(S.true)
else:
assert v
v = Or(*args)
if v.func is Or:
assert len(v.args) == 2
else:
assert v
def load(s):
"""Loads a boolean expression from a string.
Examples
========
>>> from diofant.logic.utilities.dimacs import load
>>> load('1')
cnf_1
>>> load('1 2')
Or(cnf_1, cnf_2)
>>> load('1 \\n 2')
And(cnf_1, cnf_2)
>>> load('1 2 \\n 3')
And(Or(cnf_1, cnf_2), cnf_3)
"""
clauses = []
lines = s.split('\n')
pComment = re.compile('c.*')
pStats = re.compile('p\s*cnf\s*(\d*)\s*(\d*)')
while len(lines) > 0:
line = lines.pop(0)
# Only deal with lines that aren't comments
if not pComment.match(line):
m = pStats.match(line)
if not m:
nums = line.rstrip('\n').split(' ')
list = []
for lit in nums:
if lit != '':
if int(lit) == 0:
continue
num = abs(int(lit))
sign = True
if int(lit) < 0:
sign = False
if sign:
list.append(Symbol("cnf_%s" % num))
else:
list.append(~Symbol("cnf_%s" % num))
if len(list) > 0:
clauses.append(Or(*list))
return And(*clauses)
def piecewise_fold(expr):
"""
Takes an expression containing a piecewise function and returns the
expression in piecewise form.
Examples
========
>>> from diofant import Piecewise, piecewise_fold, Integer
>>> from diofant.abc import x
>>> p = Piecewise((x, x < 1), (1, Integer(1) <= x))
>>> piecewise_fold(x*p)
Piecewise((x**2, x < 1), (x, 1 <= x))
See Also
========
diofant.functions.elementary.piecewise.Piecewise
"""
if not isinstance(expr, Basic) or not expr.has(Piecewise):
return expr
new_args = list(map(piecewise_fold, expr.args))
if expr.func is ExprCondPair:
return ExprCondPair(*new_args)
piecewise_args = []
for n, arg in enumerate(new_args):
if isinstance(arg, Piecewise):
piecewise_args.append(n)
if len(piecewise_args) > 0:
n = piecewise_args[0]
new_args = [(expr.func(*(new_args[:n] + [e] + new_args[n + 1:])), c)
for e, c in new_args[n].args]
if isinstance(expr, Boolean):
# If expr is Boolean, we must return some kind of PiecewiseBoolean.
# This is constructed by means of Or, And and Not.
# piecewise_fold(0 < Piecewise( (sin(x), x<0), (cos(x), True)))
# can't return Piecewise((0 < sin(x), x < 0), (0 < cos(x), True))
# but instead Or(And(x < 0, 0 < sin(x)), And(0 < cos(x), Not(x<0)))
other = True
rtn = False
for e, c in new_args:
rtn = Or(rtn, And(other, c, e))
other = And(other, Not(c))
if len(piecewise_args) > 1:
return piecewise_fold(rtn)
return rtn
if len(piecewise_args) > 1:
return piecewise_fold(Piecewise(*new_args))
return Piecewise(*new_args)
else:
return expr.func(*new_args)
def test_operators():
# Mostly test __and__, __rand__, and so on
assert True & A == (A & True) == A
assert False & A == (A & False) == false
assert A & B == And(A, B)
assert True | A == (A | True) == true
assert False | A == (A | False) == A
assert A | B == Or(A, B)
assert ~A == Not(A)
assert True >> A == (A << True) == A
assert False >> A == (A << False) == true
assert (A >> True) == (True << A) == true
assert (A >> False) == (False << A) == ~A
assert A >> B == B << A == Implies(A, B)
assert True ^ A == A ^ True == ~A
assert False ^ A == (A ^ False) == A
assert A ^ B == Xor(A, B)
def test_ITE():
A, B, C = map(Boolean, symbols('A,B,C'))
pytest.raises(ValueError, lambda: ITE(A, B))
assert ITE(True, False, True) is false
assert ITE(True, True, False) is true
assert ITE(False, True, False) is false
assert ITE(False, False, True) is true
assert isinstance(ITE(A, B, C), ITE)
A = True
assert ITE(A, B, C) == B
A = False
assert ITE(A, B, C) == C
B = True
assert ITE(And(A, B), B, C) == C
assert ITE(Or(A, False), And(B, True), False) is false
def test_bool_map():
"""
Test working of bool_map function.
"""
minterms = [[0, 0, 0, 1], [0, 0, 1, 1], [0, 1, 1, 1], [1, 0, 1, 1],
[1, 1, 1, 1]]
assert bool_map(Not(Not(a)), a) == (a, {a: a})
assert bool_map(SOPform([w, x, y, z], minterms),
POSform([w, x, y, z], minterms)) == \
(And(Or(Not(w), y), Or(Not(x), y), z), {x: x, w: w, z: z, y: y})
assert bool_map(SOPform([x, z, y], [[1, 0, 1]]),
SOPform([a, b, c], [[1, 0, 1]])) is not False
function1 = SOPform([x, z, y], [[1, 0, 1], [0, 0, 1]])
function2 = SOPform([a, b, c], [[1, 0, 1], [1, 0, 0]])
assert bool_map(function1, function2) == \
(function1, {y: a, z: b})
assert bool_map(And(x, Not(y)), Or(y, Not(x))) is False
assert bool_map(And(x, Not(y)), And(y, Not(x), z)) is False
assert bool_map(And(x, Not(y)), And(Or(y, z), Not(x))) is False
assert bool_map(Or(And(Not(y), a), And(Not(y), b), And(x, y)), Or(
x, y, a)) is False
def test_Or():
assert Or() is false
assert Or(A) == A
assert Or(True) is true
assert Or(False) is false
assert Or(True, True) is true
assert Or(True, False) is true
assert Or(False, False) is false
assert Or(True, A) is true
assert Or(False, A) == A
assert Or(True, False, False) is true
assert Or(True, False, A) is true
assert Or(False, False, A) == A
assert Or(2, A) is true
assert Or(A < 1, A >= 1) is true
e = A > 1
assert Or(e, e.canonical) == e
g, l, ge, le = A > B, B < A, A >= B, B <= A
assert Or(g, l, ge, le) == Or(g, ge)
def _sort_expr_cond(self, sym, a, b, targetcond=None):
"""Determine what intervals the expr, cond pairs affect.
1) If cond is True, then log it as default
1.1) Currently if cond can't be evaluated, throw NotImplementedError.
2) For each inequality, if previous cond defines part of the interval
update the new conds interval.
- eg x < 1, x < 3 -> [oo,1],[1,3] instead of [oo,1],[oo,3]
3) Sort the intervals to make it easier to find correct exprs
Under normal use, we return the expr,cond pairs in increasing order
along the real axis corresponding to the symbol sym. If targetcond
is given, we return a list of (lowerbound, upperbound) pairs for
this condition."""
from diofant.solvers.inequalities import solve_univariate_inequality
default = None
int_expr = []
expr_cond = []
or_cond = False
or_intervals = []
independent_expr_cond = []
for expr, cond in self.args:
if isinstance(cond, Or):
for cond2 in sorted(cond.args, key=default_sort_key):
expr_cond.append((expr, cond2))
else:
expr_cond.append((expr, cond))
if cond == S.true:
break
for expr, cond in expr_cond:
if cond == S.true:
independent_expr_cond.append((expr, cond))
default = self.func(*independent_expr_cond)
break
orig_cond = cond
if sym not in cond.free_symbols:
independent_expr_cond.append((expr, cond))
continue
elif isinstance(cond, Equality):
continue
elif isinstance(cond, And):
lower = S.NegativeInfinity
upper = S.Infinity
for cond2 in cond.args:
if sym not in [cond2.lts, cond2.gts]:
cond2 = solve_univariate_inequality(cond2, sym)
if cond2.lts == sym:
upper = Min(cond2.gts, upper)
elif cond2.gts == sym:
lower = Max(cond2.lts, lower)
else:
raise NotImplementedError(
"Unable to handle interval evaluation of expression."
)
else:
if sym not in [cond.lts, cond.gts]:
cond = solve_univariate_inequality(cond, sym)
lower, upper = cond.lts, cond.gts # part 1: initialize with givens
if cond.lts == sym: # part 1a: expand the side ...
lower = S.NegativeInfinity # e.g. x <= 0 ---> -oo <= 0
elif cond.gts == sym: # part 1a: ... that can be expanded
upper = S.Infinity # e.g. x >= 0 ---> oo >= 0
else:
raise NotImplementedError(
"Unable to handle interval evaluation of expression.")
# part 1b: Reduce (-)infinity to what was passed in.
lower, upper = Max(a, lower), Min(b, upper)
for n in range(len(int_expr)):
# Part 2: remove any interval overlap. For any conflicts, the
# iterval already there wins, and the incoming interval updates
# its bounds accordingly.
if self.__eval_cond(lower < int_expr[n][1]) and \
self.__eval_cond(lower >= int_expr[n][0]):
lower = int_expr[n][1]
elif len(int_expr[n][1].free_symbols) and \
self.__eval_cond(lower >= int_expr[n][0]):
if self.__eval_cond(lower == int_expr[n][0]):
lower = int_expr[n][1]
else:
int_expr[n][1] = Min(lower, int_expr[n][1])
elif len(int_expr[n][0].free_symbols) and \
self.__eval_cond(upper == int_expr[n][1]):
upper = Min(upper, int_expr[n][0])
elif len(int_expr[n][1].free_symbols) and \
(lower >= int_expr[n][0]) is not S.true and \
(int_expr[n][1] == Min(lower, upper)) is not True:
upper = Min(upper, int_expr[n][0])
elif self.__eval_cond(upper > int_expr[n][0]) and \
self.__eval_cond(upper <= int_expr[n][1]):
upper = int_expr[n][0]
elif len(int_expr[n][0].free_symbols) and \
self.__eval_cond(upper < int_expr[n][1]):
int_expr[n][0] = Max(upper, int_expr[n][0])
if self.__eval_cond(
lower >= upper) is not True: # Is it still an interval?
int_expr.append([lower, upper, expr])
if orig_cond == targetcond:
return [(lower, upper, None)]
elif isinstance(targetcond, Or) and cond in targetcond.args:
or_cond = Or(or_cond, cond)
or_intervals.append((lower, upper, None))
if or_cond == targetcond:
or_intervals.sort(key=lambda x: x[0])
return or_intervals
int_expr.sort(key=lambda x: x[1].sort_key()
if x[1].is_number else S.NegativeInfinity.sort_key())
int_expr.sort(key=lambda x: x[0].sort_key()
if x[0].is_number else S.Infinity.sort_key())
for n in range(len(int_expr)):
if len(int_expr[n][0].free_symbols) or len(
int_expr[n][1].free_symbols):
if isinstance(int_expr[n][1], Min) or int_expr[n][1] == b:
newval = Min(*int_expr[n][:-1])
if n > 0 and int_expr[n][0] == int_expr[n - 1][1]:
int_expr[n - 1][1] = newval
int_expr[n][0] = newval
else:
newval = Max(*int_expr[n][:-1])
if n < len(int_expr) - 1 and int_expr[n][1] == int_expr[
n + 1][0]:
int_expr[n + 1][0] = newval
int_expr[n][1] = newval
# Add holes to list of intervals if there is a default value,
# otherwise raise a ValueError.
holes = []
curr_low = a
for int_a, int_b, expr in int_expr:
if (curr_low < int_a) is S.true:
holes.append([curr_low, Min(b, int_a), default])
elif (curr_low >= int_a) is not S.true:
holes.append([curr_low, Min(b, int_a), default])
curr_low = Min(b, int_b)
if (curr_low < b) is S.true:
holes.append([Min(b, curr_low), b, default])
elif (curr_low >= b) is not S.true:
holes.append([Min(b, curr_low), b, default])
if holes and default is not None:
int_expr.extend(holes)
if targetcond == S.true:
return [(h[0], h[1], None) for h in holes]
elif holes and default is None:
raise ValueError("Called interval evaluation over piecewise "
"function on undefined intervals %s" %
", ".join([str((h[0], h[1])) for h in holes]))
return int_expr
def test_distribute():
assert distribute_and_over_or(Or(And(A, B), C)) == And(Or(A, C), Or(B, C))
assert distribute_or_over_and(And(A, Or(B, C))) == Or(And(A, B), And(A, C))
def test_sympyissue_10641():
assert str(Or(x < sqrt(3), x).evalf(2)) == 'x | (x < 1.7)'
assert str(And(x < sqrt(3), x).evalf(2)) == 'x & (x < 1.7)'
def test_sympyissue_8975():
assert Or(And(-oo < x, x <= -2), And(2 <= x, x < oo)).as_set() == \
Interval(-oo, -2, True) + Interval(2, oo, False, True)
def test_true_false():
assert true is true
assert false is false
assert true is not True
assert false is not False
assert true
assert not false
assert true == True # noqa: E712
assert false == False # noqa: E712
assert not (true == False) # noqa: E712
assert not (false == True) # noqa: E712
assert not (true == false)
assert hash(true) == hash(True)
assert hash(false) == hash(False)
assert len({true, True}) == len({false, False}) == 1
assert isinstance(true, BooleanAtom)
assert isinstance(false, BooleanAtom)
# We don't want to subclass from bool, because bool subclasses from
# int. But operators like &, |, ^, <<, >>, and ~ act differently on 0 and
# 1 then we want them to on true and false. See the docstrings of the
# various And, Or, etc. functions for examples.
assert not isinstance(true, bool)
assert not isinstance(false, bool)
# Note: using 'is' comparison is important here. We want these to return
# true and false, not True and False
assert Not(true) is false
assert Not(True) is false
assert Not(false) is true
assert Not(False) is true
assert ~true is false
assert ~false is true
for T, F in itertools.product([True, true], [False, false]):
assert And(T, F) is false
assert And(F, T) is false
assert And(F, F) is false
assert And(T, T) is true
assert And(T, x) == x
assert And(F, x) is false
if not (T is True and F is False):
assert T & F is false
assert F & T is false
if F is not False:
assert F & F is false
if T is not True:
assert T & T is true
assert Or(T, F) is true
assert Or(F, T) is true
assert Or(F, F) is false
assert Or(T, T) is true
assert Or(T, x) is true
assert Or(F, x) == x
if not (T is True and F is False):
assert T | F is true
assert F | T is true
if F is not False:
assert F | F is false
if T is not True:
assert T | T is true
assert Xor(T, F) is true
assert Xor(F, T) is true
assert Xor(F, F) is false
assert Xor(T, T) is false
assert Xor(T, x) == ~x
assert Xor(F, x) == x
if not (T is True and F is False):
assert T ^ F is true
assert F ^ T is true
if F is not False:
assert F ^ F is false
if T is not True:
assert T ^ T is false
assert Nand(T, F) is true
assert Nand(F, T) is true
assert Nand(F, F) is true
assert Nand(T, T) is false
assert Nand(T, x) == ~x
assert Nand(F, x) is true
assert Nor(T, F) is false
assert Nor(F, T) is false
assert Nor(F, F) is true
assert Nor(T, T) is false
assert Nor(T, x) is false
assert Nor(F, x) == ~x
assert Implies(T, F) is false
assert Implies(F, T) is true
assert Implies(F, F) is true
assert Implies(T, T) is true
assert Implies(T, x) == x
assert Implies(F, x) is true
assert Implies(x, T) is true
assert Implies(x, F) == ~x
if not (T is True and F is False):
assert T >> F is false
assert F << T is false
assert F >> T is true
assert T << F is true
if F is not False:
assert F >> F is true
assert F << F is true
if T is not True:
assert T >> T is true
assert T << T is true
assert Equivalent(T, F) is false
assert Equivalent(F, T) is false
assert Equivalent(F, F) is true
assert Equivalent(T, T) is true
assert Equivalent(T, x) == x
assert Equivalent(F, x) == ~x
assert Equivalent(x, T) == x
assert Equivalent(x, F) == ~x
assert ITE(T, T, T) is true
assert ITE(T, T, F) is true
assert ITE(T, F, T) is false
assert ITE(T, F, F) is false
assert ITE(F, T, T) is true
assert ITE(F, T, F) is false
assert ITE(F, F, T) is true
assert ITE(F, F, F) is false
def test_multivariate_bool_as_set():
And(x >= 0, y >= 0).as_set() # == Interval(0, oo)*Interval(0, oo)
Or(x >= 0, y >= 0).as_set()