from sympy.core.expr import unchanged from sympy.core.numbers import oo from sympy.core.relational import Eq from sympy.core.singleton import S from sympy.core.symbol import Symbol from sympy.sets.contains import Contains from sympy.sets.sets import (FiniteSet, Interval) from sympy.testing.pytest import raises def test_contains_basic(): raises(TypeError, lambda: Contains(S.Integers, 1)) assert Contains(2, S.Integers) is S.true assert Contains(-2, S.Naturals) is S.false i = Symbol('i', integer=True) assert Contains(i, S.Naturals) == Contains(i, S.Naturals, evaluate=False) def test_issue_6194(): x = Symbol('x') assert unchanged(Contains, x, Interval(0, 1)) assert Interval(0, 1).contains(x) == (S.Zero <= x) & (x <= 1) assert Contains(x, FiniteSet(0)) != S.false assert Contains(x, Interval(1, 1)) != S.false assert Contains(x, S.Integers) != S.false def test_issue_10326(): assert Contains(oo, Interval(-oo, oo)) == False assert Contains(-oo, Interval(-oo, oo)) == False def test_binary_symbols(): x = Symbol('x') y = Symbol('y') z = Symbol('z') assert Contains(x, FiniteSet(y, Eq(z, True)) ).binary_symbols == {y, z} def test_as_set(): x = Symbol('x') y = Symbol('y') assert Contains(x, FiniteSet(y)).as_set() == FiniteSet(y) assert Contains(x, S.Integers).as_set() == S.Integers assert Contains(x, S.Reals).as_set() == S.Reals def test_type_error(): # Pass in a parameter not of type "set" raises(TypeError, lambda: Contains(2, None))