f true xs f eq s length xs length cons a xs cons a xs length nil 0 length cons x xs s length xs eq 0 0 true eq s x 0 false eq 0 s y false eq s x s y eq x y f 2 true 0 eq 2 s 1 length 1 cons 2 a 0 nil 0 0 0 false 0 FULL emmes-nonloop-ex7_1.trs