'Irrational number predicate.
``Q.irrational(x)`` is true iff ``x``  is any real number that
cannot be expressed as a ratio of integers.
Examples
>>> from sympy import ask, Q, pi, S, I
>>> ask(Q.irrational(0))
False
>>> ask(Q.irrational(S(1)/2))
False
>>> ask(Q.irrational(pi))
True
>>> ask(Q.irrational(I))
False
References
.. [1] https://en.wikipedia.org/wiki/Irrational_number'

@predicate_memo
def irrational(self):

    return Predicate('irrational')
