map F nil nil map Z cons U V cons Z U map Z V comp I J X1 I J X1 twice Z1 comp Z1 Z1 F a a Z a a U a V b I c c J c c X1 c Z1 c c comp c c c c c c cons a b b map a a b b nil b twice c c c c FULL benchmarks/applicative/AotoYamada_05__026.atrs