from __future__ import division from sympy.assumptions.ask import Q from sympy.core.containers import Tuple from sympy.core.numbers import oo from sympy.core.relational import Equality, Eq, Ne from sympy.core.singleton import S from sympy.core.symbol import (Dummy, symbols) from sympy.functions import Piecewise from sympy.functions.elementary.trigonometric import sin from sympy.sets.sets import (EmptySet, Interval, Union) from sympy.simplify.simplify import simplify from sympy.logic.boolalg import ( And, Boolean, Equivalent, ITE, Implies, Nand, Nor, Not, Or, POSform, SOPform, Xor, Xnor, conjuncts, disjuncts, distribute_or_over_and, distribute_and_over_or, eliminate_implications, is_nnf, is_cnf, is_dnf, simplify_logic, to_nnf, to_cnf, to_dnf, to_int_repr, bool_map, true, false, BooleanAtom, is_literal, term_to_integer, integer_to_term, truth_table, as_Boolean) from sympy.utilities.pytest import raises, XFAIL from sympy.utilities import cartes A, B, C, D = symbols('A:D') a, b, c, d, e, w, x, y, z = symbols('a:e w:z') 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_And(): assert And() is true assert And(A) == A assert And(True) is true assert And(False) is false assert And(True, True ) is true assert And(True, False) is false assert And(False, False) is false assert And(True, A) == A assert And(False, A) is false assert And(True, True, True) is true assert And(True, True, A) == A assert And(True, False, A) is false assert And(1, A) == A raises(TypeError, lambda: And(2, A)) raises(TypeError, lambda: And(A < 2, A)) assert And(A < 1, A >= 1) is false e = A > 1 assert And(e, e.canonical) == e.canonical g, l, ge, le = A > B, B < A, A >= B, B <= A assert And(g, l, ge, le) == And(l, le) 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(1, A) is true raises(TypeError, lambda: Or(2, A)) raises(TypeError, lambda: Or(A < 2, A)) 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 test_Xor(): assert Xor() is false assert Xor(A) == A assert Xor(A, A) is false assert Xor(True, A, A) is true assert Xor(A, A, A, A, A) == A assert Xor(True, False, False, A, B) == ~Xor(A, B) assert Xor(True) is true assert Xor(False) is false assert Xor(True, True ) is false assert Xor(True, False) is true assert Xor(False, False) is false assert Xor(True, A) == ~A assert Xor(False, A) == A assert Xor(True, False, False) is true assert Xor(True, False, A) == ~A assert Xor(False, False, A) == A assert isinstance(Xor(A, B), Xor) assert Xor(A, B, Xor(C, D)) == Xor(A, B, C, D) assert Xor(A, B, Xor(B, C)) == Xor(A, C) assert Xor(A < 1, A >= 1, B) == Xor(0, 1, B) == Xor(1, 0, B) e = A > 1 assert Xor(e, e.canonical) == Xor(0, 0) == Xor(1, 1) def test_Not(): raises(TypeError, lambda: Not(True, False)) assert Not(True) is false assert Not(False) is true assert Not(0) is true assert Not(1) is false assert Not(2) is false def test_Nand(): assert Nand() is false assert Nand(A) == ~A assert Nand(True) is false assert Nand(False) is true assert Nand(True, True ) is false assert Nand(True, False) is true assert Nand(False, False) is true assert Nand(True, A) == ~A assert Nand(False, A) is true assert Nand(True, True, True) is false assert Nand(True, True, A) == ~A assert Nand(True, False, A) is true def test_Nor(): assert Nor() is true assert Nor(A) == ~A assert Nor(True) is false assert Nor(False) is true assert Nor(True, True ) is false assert Nor(True, False) is false assert Nor(False, False) is true assert Nor(True, A) is false assert Nor(False, A) == ~A assert Nor(True, True, True) is false assert Nor(True, True, A) is false assert Nor(True, False, A) is false def test_Xnor(): assert Xnor() is true assert Xnor(A) == ~A assert Xnor(A, A) is true assert Xnor(True, A, A) is false assert Xnor(A, A, A, A, A) == ~A assert Xnor(True) is false assert Xnor(False) is true assert Xnor(True, True ) is true assert Xnor(True, False) is false assert Xnor(False, False) is true assert Xnor(True, A) == A assert Xnor(False, A) == ~A assert Xnor(True, False, False) is false assert Xnor(True, False, A) == A assert Xnor(False, False, A) == ~A def test_Implies(): raises(ValueError, lambda: Implies(A, B, C)) assert Implies(True, True) is true assert Implies(True, False) is false assert Implies(False, True) is true assert Implies(False, False) is true assert Implies(0, A) is true assert Implies(1, 1) is true assert Implies(1, 0) is false assert A >> B == B << A assert (A < 1) >> (A >= 1) == (A >= 1) assert (A < 1) >> (S(1) > A) is true assert A >> A is true def test_Equivalent(): assert Equivalent(A, B) == Equivalent(B, A) == Equivalent(A, B, A) assert Equivalent() is true assert Equivalent(A, A) == Equivalent(A) is true assert Equivalent(True, True) == Equivalent(False, False) is true assert Equivalent(True, False) == Equivalent(False, True) is false assert Equivalent(A, True) == A assert Equivalent(A, False) == Not(A) assert Equivalent(A, B, True) == A & B assert Equivalent(A, B, False) == ~A & ~B assert Equivalent(1, A) == A assert Equivalent(0, A) == Not(A) assert Equivalent(A, Equivalent(B, C)) != Equivalent(Equivalent(A, B), C) assert Equivalent(A < 1, A >= 1) is false assert Equivalent(A < 1, A >= 1, 0) is false assert Equivalent(A < 1, A >= 1, 1) is false assert Equivalent(A < 1, S(1) > A) == Equivalent(1, 1) == Equivalent(0, 0) assert Equivalent(Equality(A, B), Equality(B, A)) is true 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 def test_simplification(): """ Test working of simplification methods. """ set1 = [[0, 0, 1], [0, 1, 1], [1, 0, 0], [1, 1, 0]] set2 = [[0, 0, 0], [0, 1, 0], [1, 0, 1], [1, 1, 1]] assert SOPform([x, y, z], set1) == Or(And(Not(x), z), And(Not(z), x)) assert Not(SOPform([x, y, z], set2)) == Not(Or(And(Not(x), Not(z)), And(x, z))) assert POSform([x, y, z], set1 + set2) is true assert SOPform([x, y, z], set1 + set2) is true assert SOPform([Dummy(), Dummy(), Dummy()], set1 + set2) is true minterms = [[0, 0, 0, 1], [0, 0, 1, 1], [0, 1, 1, 1], [1, 0, 1, 1], [1, 1, 1, 1]] dontcares = [[0, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 1]] assert ( SOPform([w, x, y, z], minterms, dontcares) == Or(And(Not(w), z), And(y, z))) assert POSform([w, x, y, z], minterms, dontcares) == And(Or(Not(w), y), z) # test simplification ans = And(A, Or(B, C)) assert simplify_logic(A & (B | C)) == ans assert simplify_logic((A & B) | (A & C)) == ans assert simplify_logic(Implies(A, B)) == Or(Not(A), B) assert simplify_logic(Equivalent(A, B)) == \ Or(And(A, B), And(Not(A), Not(B))) assert simplify_logic(And(Equality(A, 2), C)) == And(Equality(A, 2), C) assert simplify_logic(And(Equality(A, 2), A)) is S.false assert simplify_logic(And(Equality(A, 2), A)) == And(Equality(A, 2), A) assert simplify_logic(And(Equality(A, B), C)) == And(Equality(A, B), C) assert simplify_logic(Or(And(Equality(A, 3), B), And(Equality(A, 3), C))) \ == And(Equality(A, 3), Or(B, C)) b = (~x & ~y & ~z) | ( ~x & ~y & z) e = And(A, b) assert simplify_logic(e) == A & ~x & ~y # check input ans = SOPform([x, y], [[1, 0]]) assert SOPform([x, y], [[1, 0]]) == ans assert POSform([x, y], [[1, 0]]) == ans raises(ValueError, lambda: SOPform([x], [[1]], [[1]])) assert SOPform([x], [[1]], [[0]]) is true assert SOPform([x], [[0]], [[1]]) is true assert SOPform([x], [], []) is false raises(ValueError, lambda: POSform([x], [[1]], [[1]])) assert POSform([x], [[1]], [[0]]) is true assert POSform([x], [[0]], [[1]]) is true assert POSform([x], [], []) is false # check working of simplify assert simplify((A & B) | (A & C)) == And(A, Or(B, C)) assert simplify(And(x, Not(x))) == False assert simplify(Or(x, Not(x))) == True 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]])) != 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_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_is_boolean(): assert true.is_Boolean assert (A & B).is_Boolean assert (A | B).is_Boolean assert (~A).is_Boolean assert (A ^ B).is_Boolean def test_subs(): assert (A & B).subs(A, True) == B assert (A & B).subs(A, False) is false assert (A & B).subs(B, True) == A assert (A & B).subs(B, False) is false assert (A & B).subs({A: True, B: True}) is true assert (A | B).subs(A, True) is true assert (A | B).subs(A, False) == B assert (A | B).subs(B, True) is true assert (A | B).subs(B, False) == A assert (A | B).subs({A: True, B: True}) is true """ we test for axioms of boolean algebra see http://en.wikipedia.org/wiki/Boolean_algebra_(structure) """ def test_commutative(): """Test for commutativity of And and Or""" A, B = map(Boolean, symbols('A,B')) assert A & B == B & A assert A | B == B | A def test_and_associativity(): """Test for associativity of And""" assert (A & B) & C == A & (B & C) def test_or_assicativity(): assert ((A | B) | C) == (A | (B | C)) def test_double_negation(): a = Boolean() assert ~(~a) == a # test methods def test_eliminate_implications(): 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_conjuncts(): assert conjuncts(A & B & C) == {A, B, C} assert conjuncts((A | B) & C) == {A | B, C} assert conjuncts(A) == {A} assert conjuncts(True) == {True} assert conjuncts(False) == {False} def test_disjuncts(): assert disjuncts(A | B | C) == {A, B, C} assert disjuncts((A | B) & C) == {(A | B) & C} assert disjuncts(A) == {A} assert disjuncts(True) == {True} assert disjuncts(False) == {False} 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_to_nnf(): assert to_nnf(true) is true assert to_nnf(false) is false assert to_nnf(A) == 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)) assert ITE(A, 1, 0).to_nnf() == A assert ITE(A, 0, 1).to_nnf() == ~A # although ITE can hold non-Boolean, it will complain if # an attempt is made to convert the ITE to Boolean nnf raises(TypeError, lambda: ITE(A < 1, [1], B).to_nnf()) 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))) def test_to_dnf(): 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 test_to_int_repr(): x, y, z = map(Boolean, symbols('x,y,z')) def sorted_recursive(arg): try: return sorted(sorted_recursive(x) for x in arg) except TypeError: # arg is not a sequence return arg assert sorted_recursive(to_int_repr([x | y, z | x], [x, y, z])) == \ sorted_recursive([[1, 2], [1, 3]]) assert sorted_recursive(to_int_repr([x | y, z | ~x], [x, y, z])) == \ sorted_recursive([[1, 2], [3, -1]]) 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_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 def test_is_dnf(): assert is_dnf(x) is True assert is_dnf(x | y | z) is True assert is_dnf(x & y & z) is True assert is_dnf((x & y) | z) is True assert is_dnf((x | y) & z) is False def test_ITE(): A, B, C = symbols('A:C') 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 assert ITE(x, A, B) == Not(x) assert ITE(x, B, A) == x assert ITE(1, x, y) == x assert ITE(0, x, y) == y raises(TypeError, lambda: ITE(2, x, y)) raises(TypeError, lambda: ITE(1, [], y)) raises(TypeError, lambda: ITE(1, (), y)) raises(TypeError, lambda: ITE(1, y, [])) assert ITE(1, 1, 1) is S.true assert isinstance(ITE(1, 1, 1, evaluate=False), ITE) raises(TypeError, lambda: ITE(x > 1, y, x)) assert ITE(Eq(x, True), y, x) == ITE(x, y, x) assert ITE(Eq(x, False), y, x) == ITE(~x, y, x) assert ITE(Ne(x, True), y, x) == ITE(~x, y, x) assert ITE(Ne(x, False), y, x) == ITE(x, y, x) # 0 and 1 in the context are not treated as True/False # so the equality must always be False since dissimilar # objects cannot be equal assert ITE(Eq(x, 0), y, x) == x assert ITE(Eq(x, 1), y, x) == x assert ITE(Ne(x, 0), y, x) == y assert ITE(Ne(x, 1), y, x) == y assert ITE(Eq(x, 0), y, z).subs(x, 0) == y assert ITE(Eq(x, 0), y, z).subs(x, 1) == z 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(Q.zero(A)) is True assert is_literal(Not(Q.zero(A))) is True assert is_literal(Or(A, B)) is False assert is_literal(And(Q.zero(A), Q.zero(B))) is False 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_true_false(): assert true is S.true assert false is S.false assert true is not True assert false is not False assert true assert not false assert true == True assert false == False assert not (true == False) assert not (false == True) 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 cartes([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 not F is False: assert F & F is false if not T is 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 not F is False: assert F | F is false if not T is 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 not F is False: assert F ^ F is false if not T is 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 not F is False: assert F >> F is true assert F << F is true if not T is 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 assert all(i.simplify(1, 2) is i for i in (S.true, S.false)) def test_bool_as_set(): assert ITE(y <= 0, False, y >= 1).as_set() == Interval(1, oo) assert And(x <= 2, x >= -2).as_set() == Interval(-2, 2) assert Or(x >= 2, x <= -2).as_set() == Interval(-oo, -2) + Interval(2, oo) assert Not(x > 2).as_set() == Interval(-oo, 2) # issue 10240 assert Not(And(x > 2, x < 3)).as_set() == \ Union(Interval(-oo,2),Interval(3,oo)) assert true.as_set() == S.UniversalSet assert false.as_set() == EmptySet() assert x.as_set() == S.UniversalSet assert And(Or(x < 1, x > 3), x < 2 ).as_set() == Interval.open(-oo, 1) assert And(x < 1, sin(x) < 3).as_set() == (x < 1).as_set() raises(NotImplementedError, lambda: (sin(x) < 1).as_set()) @XFAIL def test_multivariate_bool_as_set(): x, y = symbols('x,y') assert And(x >= 0, y >= 0).as_set() == Interval(0, oo)*Interval(0, oo) assert Or(x >= 0, y >= 0).as_set() == S.Reals*S.Reals - \ Interval(-oo, 0, True, True)*Interval(-oo, 0, True, True) def test_all_or_nothing(): x = symbols('x', 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 == True v = Or(*args) if v.func is Or: assert len(v.args) == 2 else: assert v == True def test_canonical_atoms(): assert true.canonical == true assert false.canonical == false def test_issue_8777(): assert And(x > 2, x < oo).as_set() == Interval(2, oo, left_open=True) assert And(x >= 1, x < oo).as_set() == Interval(1, oo) assert (x < oo).as_set() == Interval(-oo, oo) assert (x > -oo).as_set() == Interval(-oo, oo) def test_issue_8975(): assert Or(And(-oo < x, x <= -2), And(2 <= x, x < oo)).as_set() == \ Interval(-oo, -2) + Interval(2, oo) def test_term_to_integer(): assert term_to_integer([1, 0, 1, 0, 0, 1, 0]) == 82 assert term_to_integer('0010101000111001') == 10809 def test_integer_to_term(): assert integer_to_term(777) == [1, 1, 0, 0, 0, 0, 1, 0, 0, 1] assert integer_to_term(123, 3) == [1, 1, 1, 1, 0, 1, 1] assert integer_to_term(456, 16) == [0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0] def test_truth_table(): assert list(truth_table(And(x, y), [x, y], input=False)) == [False, False, False, True] assert list(truth_table(x | y, [x, y], input=False)) == [False, True, True, True] assert list(truth_table(x >> y, [x, y], input=False)) == [True, True, False, True] def test_issue_8571(): for t in (S.true, S.false): raises(TypeError, lambda: +t) raises(TypeError, lambda: -t) raises(TypeError, lambda: abs(t)) # use int(bool(t)) to get 0 or 1 raises(TypeError, lambda: int(t)) for o in [S.Zero, S.One, x]: for _ in range(2): raises(TypeError, lambda: o + t) raises(TypeError, lambda: o - t) raises(TypeError, lambda: o % t) raises(TypeError, lambda: o*t) raises(TypeError, lambda: o/t) raises(TypeError, lambda: o**t) o, t = t, o # do again in reversed order def test_expand_relational(): n = symbols('n', negative=True) p, q = symbols('p q', positive=True) r = ((n + q*(-n/q + 1))/(q*(-n/q + 1)) < 0) assert r is not S.false assert r.expand() is S.false assert (q > 0).expand() is S.true def test_issue_12717(): assert S.true.is_Atom == True assert S.false.is_Atom == True def test_as_Boolean(): nz = symbols('nz', nonzero=True) assert all(as_Boolean(i) is S.true for i in (True, S.true, 1, nz)) z = symbols('z', zero=True) assert all(as_Boolean(i) is S.false for i in (False, S.false, 0, z)) assert all(as_Boolean(i) == i for i in (x, x < 0)) for i in (2, S(2), x + 1, []): raises(TypeError, lambda: as_Boolean(i)) def test_binary_symbols(): assert ITE(x < 1, y, z).binary_symbols == set((y, z)) for f in (Eq, Ne): assert f(x, 1).binary_symbols == set() assert f(x, True).binary_symbols == set([x]) assert f(x, False).binary_symbols == set([x]) assert S.true.binary_symbols == set() assert S.false.binary_symbols == set() assert x.binary_symbols == set([x]) assert And(x, Eq(y, False), Eq(z, 1)).binary_symbols == set([x, y]) assert Q.prime(x).binary_symbols == set() assert Q.is_true(x < 1).binary_symbols == set() assert Q.is_true(x).binary_symbols == set([x]) assert Q.is_true(Eq(x, True)).binary_symbols == set([x]) assert Q.prime(x).binary_symbols == set() def test_BooleanFunction_diff(): assert And(x, y).diff(x) == Piecewise((0, Eq(False, y)), (1, True))