def is_strict_inequality_symbol(sym,pol=0):
    """ Determine whether an inequality symbol is strict under a given
    number of negations, where pol == 0 indicates an even number, pol
    == 1 an odd number and None indicates neither even nor odd."""

    return sym.name in ['<','>'] if pol == 0 else sym.name in ['<=','>='] if pol == 1 else False