YES Problem: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) active(2nd(X)) -> 2nd(active(X)) active(cons(X1,X2)) -> cons(active(X1),X2) active(from(X)) -> from(active(X)) active(s(X)) -> s(active(X)) 2nd(mark(X)) -> mark(2nd(X)) cons(mark(X1),X2) -> mark(cons(X1,X2)) from(mark(X)) -> mark(from(X)) s(mark(X)) -> mark(s(X)) proper(2nd(X)) -> 2nd(proper(X)) proper(cons(X1,X2)) -> cons(proper(X1),proper(X2)) proper(from(X)) -> from(proper(X)) proper(s(X)) -> s(proper(X)) 2nd(ok(X)) -> ok(2nd(X)) cons(ok(X1),ok(X2)) -> ok(cons(X1,X2)) from(ok(X)) -> ok(from(X)) s(ok(X)) -> ok(s(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Proof: DP Processor: DPs: active#(from(X)) -> s#(X) active#(from(X)) -> from#(s(X)) active#(from(X)) -> cons#(X,from(s(X))) active#(2nd(X)) -> active#(X) active#(2nd(X)) -> 2nd#(active(X)) active#(cons(X1,X2)) -> active#(X1) active#(cons(X1,X2)) -> cons#(active(X1),X2) active#(from(X)) -> active#(X) active#(from(X)) -> from#(active(X)) active#(s(X)) -> active#(X) active#(s(X)) -> s#(active(X)) 2nd#(mark(X)) -> 2nd#(X) cons#(mark(X1),X2) -> cons#(X1,X2) from#(mark(X)) -> from#(X) s#(mark(X)) -> s#(X) proper#(2nd(X)) -> proper#(X) proper#(2nd(X)) -> 2nd#(proper(X)) proper#(cons(X1,X2)) -> proper#(X2) proper#(cons(X1,X2)) -> proper#(X1) proper#(cons(X1,X2)) -> cons#(proper(X1),proper(X2)) proper#(from(X)) -> proper#(X) proper#(from(X)) -> from#(proper(X)) proper#(s(X)) -> proper#(X) proper#(s(X)) -> s#(proper(X)) 2nd#(ok(X)) -> 2nd#(X) cons#(ok(X1),ok(X2)) -> cons#(X1,X2) from#(ok(X)) -> from#(X) s#(ok(X)) -> s#(X) top#(mark(X)) -> proper#(X) top#(mark(X)) -> top#(proper(X)) top#(ok(X)) -> active#(X) top#(ok(X)) -> top#(active(X)) TRS: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) active(2nd(X)) -> 2nd(active(X)) active(cons(X1,X2)) -> cons(active(X1),X2) active(from(X)) -> from(active(X)) active(s(X)) -> s(active(X)) 2nd(mark(X)) -> mark(2nd(X)) cons(mark(X1),X2) -> mark(cons(X1,X2)) from(mark(X)) -> mark(from(X)) s(mark(X)) -> mark(s(X)) proper(2nd(X)) -> 2nd(proper(X)) proper(cons(X1,X2)) -> cons(proper(X1),proper(X2)) proper(from(X)) -> from(proper(X)) proper(s(X)) -> s(proper(X)) 2nd(ok(X)) -> ok(2nd(X)) cons(ok(X1),ok(X2)) -> ok(cons(X1,X2)) from(ok(X)) -> ok(from(X)) s(ok(X)) -> ok(s(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Matrix Interpretation Processor: dim=1 interpretation: [top#](x0) = 2x0 + 3, [proper#](x0) = 2x0, [2nd#](x0) = 2x0, [cons#](x0, x1) = 2x0 + x1, [from#](x0) = x0, [s#](x0) = 2x0, [active#](x0) = 3x0 + 1, [top](x0) = 7/2, [ok](x0) = 3x0 + 2, [proper](x0) = x0, [s](x0) = 2x0 + 1/2, [from](x0) = 2x0 + 1/2, [mark](x0) = x0 + 1/2, [active](x0) = 3x0 + 1, [2nd](x0) = 3x0 + 2, [cons](x0, x1) = 2x0 + x1 + 1/2 orientation: active#(from(X)) = 6X + 5/2 >= 2X = s#(X) active#(from(X)) = 6X + 5/2 >= 2X + 1/2 = from#(s(X)) active#(from(X)) = 6X + 5/2 >= 6X + 3/2 = cons#(X,from(s(X))) active#(2nd(X)) = 9X + 7 >= 3X + 1 = active#(X) active#(2nd(X)) = 9X + 7 >= 6X + 2 = 2nd#(active(X)) active#(cons(X1,X2)) = 6X1 + 3X2 + 5/2 >= 3X1 + 1 = active#(X1) active#(cons(X1,X2)) = 6X1 + 3X2 + 5/2 >= 6X1 + X2 + 2 = cons#(active(X1),X2) active#(from(X)) = 6X + 5/2 >= 3X + 1 = active#(X) active#(from(X)) = 6X + 5/2 >= 3X + 1 = from#(active(X)) active#(s(X)) = 6X + 5/2 >= 3X + 1 = active#(X) active#(s(X)) = 6X + 5/2 >= 6X + 2 = s#(active(X)) 2nd#(mark(X)) = 2X + 1 >= 2X = 2nd#(X) cons#(mark(X1),X2) = 2X1 + X2 + 1 >= 2X1 + X2 = cons#(X1,X2) from#(mark(X)) = X + 1/2 >= X = from#(X) s#(mark(X)) = 2X + 1 >= 2X = s#(X) proper#(2nd(X)) = 6X + 4 >= 2X = proper#(X) proper#(2nd(X)) = 6X + 4 >= 2X = 2nd#(proper(X)) proper#(cons(X1,X2)) = 4X1 + 2X2 + 1 >= 2X2 = proper#(X2) proper#(cons(X1,X2)) = 4X1 + 2X2 + 1 >= 2X1 = proper#(X1) proper#(cons(X1,X2)) = 4X1 + 2X2 + 1 >= 2X1 + X2 = cons#(proper(X1),proper(X2)) proper#(from(X)) = 4X + 1 >= 2X = proper#(X) proper#(from(X)) = 4X + 1 >= X = from#(proper(X)) proper#(s(X)) = 4X + 1 >= 2X = proper#(X) proper#(s(X)) = 4X + 1 >= 2X = s#(proper(X)) 2nd#(ok(X)) = 6X + 4 >= 2X = 2nd#(X) cons#(ok(X1),ok(X2)) = 6X1 + 3X2 + 6 >= 2X1 + X2 = cons#(X1,X2) from#(ok(X)) = 3X + 2 >= X = from#(X) s#(ok(X)) = 6X + 4 >= 2X = s#(X) top#(mark(X)) = 2X + 4 >= 2X = proper#(X) top#(mark(X)) = 2X + 4 >= 2X + 3 = top#(proper(X)) top#(ok(X)) = 6X + 7 >= 3X + 1 = active#(X) top#(ok(X)) = 6X + 7 >= 6X + 5 = top#(active(X)) active(2nd(cons(X,cons(Y,Z)))) = 18X + 18Y + 9Z + 16 >= Y + 1/2 = mark(Y) active(from(X)) = 6X + 5/2 >= 6X + 5/2 = mark(cons(X,from(s(X)))) active(2nd(X)) = 9X + 7 >= 9X + 5 = 2nd(active(X)) active(cons(X1,X2)) = 6X1 + 3X2 + 5/2 >= 6X1 + X2 + 5/2 = cons(active(X1),X2) active(from(X)) = 6X + 5/2 >= 6X + 5/2 = from(active(X)) active(s(X)) = 6X + 5/2 >= 6X + 5/2 = s(active(X)) 2nd(mark(X)) = 3X + 7/2 >= 3X + 5/2 = mark(2nd(X)) cons(mark(X1),X2) = 2X1 + X2 + 3/2 >= 2X1 + X2 + 1 = mark(cons(X1,X2)) from(mark(X)) = 2X + 3/2 >= 2X + 1 = mark(from(X)) s(mark(X)) = 2X + 3/2 >= 2X + 1 = mark(s(X)) proper(2nd(X)) = 3X + 2 >= 3X + 2 = 2nd(proper(X)) proper(cons(X1,X2)) = 2X1 + X2 + 1/2 >= 2X1 + X2 + 1/2 = cons(proper(X1),proper(X2)) proper(from(X)) = 2X + 1/2 >= 2X + 1/2 = from(proper(X)) proper(s(X)) = 2X + 1/2 >= 2X + 1/2 = s(proper(X)) 2nd(ok(X)) = 9X + 8 >= 9X + 8 = ok(2nd(X)) cons(ok(X1),ok(X2)) = 6X1 + 3X2 + 13/2 >= 6X1 + 3X2 + 7/2 = ok(cons(X1,X2)) from(ok(X)) = 6X + 9/2 >= 6X + 7/2 = ok(from(X)) s(ok(X)) = 6X + 9/2 >= 6X + 7/2 = ok(s(X)) top(mark(X)) = 7/2 >= 7/2 = top(proper(X)) top(ok(X)) = 7/2 >= 7/2 = top(active(X)) problem: DPs: TRS: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) active(2nd(X)) -> 2nd(active(X)) active(cons(X1,X2)) -> cons(active(X1),X2) active(from(X)) -> from(active(X)) active(s(X)) -> s(active(X)) 2nd(mark(X)) -> mark(2nd(X)) cons(mark(X1),X2) -> mark(cons(X1,X2)) from(mark(X)) -> mark(from(X)) s(mark(X)) -> mark(s(X)) proper(2nd(X)) -> 2nd(proper(X)) proper(cons(X1,X2)) -> cons(proper(X1),proper(X2)) proper(from(X)) -> from(proper(X)) proper(s(X)) -> s(proper(X)) 2nd(ok(X)) -> ok(2nd(X)) cons(ok(X1),ok(X2)) -> ok(cons(X1,X2)) from(ok(X)) -> ok(from(X)) s(ok(X)) -> ok(s(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Qed