f true xs f eq s length xs length cons a xs append xs cons b nil 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 append xs ys appendAkk reverse xs ys appendAkk nil ys ys appendAkk cons x xs ys appendAkk xs cons x ys reverse nil nil reverse cons x xs append reverse xs cons x nil f 2 true 0 eq 2 s 1 length 1 cons 2 a 0 append 2 b 0 nil 0 0 0 false 0 appendAkk 2 reverse 1 FULL emmes-nonloop-ex7_6.trs