def p_exp_1(self, p):
        "exp : EMINUS NUMBER"
        if DEBUG:
            self.print_p(p)
        p[0] = "e-{0}".format(p[2])
def p_exp_1(self, p):
        "exp : EMINUS NUMBER"
        if DEBUG:
            self.print_p(p)
        p[0] = "e-{0}".format(p[2])
exp : EMINUS NUMBER