'Internal version of format with cached results.
Returns
tuple
(equality constraints, inequality constraints)'

@pu.lazyprop
def __format(self):

    leq_constr = [lu.create_geq(self.t)]
    for elem in self.x_elems:
        leq_constr.append(lu.create_geq(elem))
    return ([], leq_constr)
