'Zero number predicate.
``ask(Q.zero(x))`` is true iff the value of ``x`` is zero.
Examples
>>> from sympy import ask, Q, oo, symbols
>>> x, y = symbols(\'x, y\')
>>> ask(Q.zero(0))
True
>>> ask(Q.zero(1/oo))
True
>>> ask(Q.zero(0*oo))
False
>>> ask(Q.zero(1))
False
>>> ask(Q.zero(x*y), Q.zero(x) | Q.zero(y))
True'

@predicate_memo
def zero(self):

    return Predicate('zero')
