def test_atoms():
x = Symbol('x')
y = Symbol('y')
assert list((1+x).atoms()) == [1,x]
assert list(x.atoms()) == [x]
assert list((1+2*cos(x)).atoms(type=Symbol)) == [x]
assert list((2*(x**(y**x))).atoms()) == [2,x,y]
assert list(Rational(1,2).atoms()) == [Rational(1,2)]
assert list(Rational(1,2).atoms(type=type(oo))) == []
