YES TRS: natsFrom(N) -> cons(N,n__natsFrom(s(N))) fst(pair(XS,YS)) -> XS snd(pair(XS,YS)) -> YS splitAt(0(),XS) -> pair(nil(),XS) splitAt(s(N),cons(X,XS)) -> u(splitAt(N,activate(XS)),N,X,activate(XS)) u(pair(YS,ZS),N,X,XS) -> pair(cons(activate(X),YS),ZS) head(cons(N,XS)) -> N tail(cons(N,XS)) -> activate(XS) sel(N,XS) -> head(afterNth(N,XS)) take(N,XS) -> fst(splitAt(N,XS)) afterNth(N,XS) -> snd(splitAt(N,XS)) natsFrom(X) -> n__natsFrom(X) activate(n__natsFrom(X)) -> natsFrom(X) activate(X) -> X max/plus interpretations on N: natsFrom_A(x1) = max{3, 4 + x1} natsFrom#_A(x1) = max{3, 4 + x1} cons_A(x1,x2) = max{4, x1, x2} cons#_A(x1,x2) = max{4, x1, x2} n__natsFrom_A(x1) = max{3, 4 + x1} n__natsFrom#_A(x1) = max{3, 4 + x1} s_A(x1) = max{0, x1} s#_A(x1) = max{0, x1} fst_A(x1) = max{12, 2 + x1} fst#_A(x1) = max{12, 2 + x1} pair_A(x1,x2) = max{3, 2 + x1, 5 + x2} pair#_A(x1,x2) = max{3, 2 + x1, 5 + x2} snd_A(x1) = max{14, 4 + x1} snd#_A(x1) = max{14, 4 + x1} splitAt_A(x1,x2) = max{10, 1 + x1, 6 + x2} splitAt#_A(x1,x2) = max{10, 1 + x1, 6 + x2} 0_A = 12 0#_A = 12 nil_A = 11 nil#_A = 11 u_A(x1,x2,x3,x4) = max{0, x1, x2, 3 + x3, 6 + x4} u#_A(x1,x2,x3,x4) = max{0, x1, x2, 3 + x3, 6 + x4} activate_A(x1) = max{4, x1} activate#_A(x1) = max{4, x1} head_A(x1) = max{15, 1 + x1} head#_A(x1) = max{15, 1 + x1} tail_A(x1) = max{5, 5 + x1} tail#_A(x1) = max{5, 5 + x1} sel_A(x1,x2) = max{13, 15 + x1, 13 + x2} sel#_A(x1,x2) = max{13, 15 + x1, 13 + x2} afterNth_A(x1,x2) = max{14, 13 + x1, 11 + x2} afterNth#_A(x1,x2) = max{14, 13 + x1, 11 + x2} take_A(x1,x2) = max{11, 12 + x1, 11 + x2} take#_A(x1,x2) = max{11, 12 + x1, 11 + x2} precedence: sel > head = afterNth = take > fst = snd = splitAt = 0 > s = nil = u = tail > pair = activate > natsFrom > cons = n__natsFrom