'Checks that both arguments are vectors, and the first is constant.'

def validate_arguments(self):

    if ((not self.args[0].is_vector()) or (not self.args[1].is_vector())):
        raise ValueError('The    arguments    to    conv    must    resolve    to    vectors.')
    if (not self.args[0].is_constant()):
        raise ValueError('The    first    argument    to    conv    must    be    constant.')
