f true xs f isList xs append cons a nil xs isList nil true isList cons x xs isList xs 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 isList 1 append 2 cons 2 a 0 nil 0 appendAkk 2 reverse 1 FULL emmes-nonloop-ex6_2.trs