prime 0 false prime s 0 false prime s s x prime1 s s x s x prime1 x 0 false prime1 x s 0 true prime1 x s s y and not divp s s y x prime1 x s y divp x y = rem x y 0 prime 1 0 0 false 0 s 1 prime1 2 true 0 and 2 not 1 divp 2 = 2 rem 2 FULL ./TRS/SK90/2.29.trs