YES Problem: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) mark(2nd(X)) -> active(2nd(mark(X))) mark(cons(X1,X2)) -> active(cons(mark(X1),X2)) mark(from(X)) -> active(from(mark(X))) mark(s(X)) -> active(s(mark(X))) 2nd(mark(X)) -> 2nd(X) 2nd(active(X)) -> 2nd(X) cons(mark(X1),X2) -> cons(X1,X2) cons(X1,mark(X2)) -> cons(X1,X2) cons(active(X1),X2) -> cons(X1,X2) cons(X1,active(X2)) -> cons(X1,X2) from(mark(X)) -> from(X) from(active(X)) -> from(X) s(mark(X)) -> s(X) s(active(X)) -> s(X) Proof: DP Processor: DPs: active#(2nd(cons(X,cons(Y,Z)))) -> mark#(Y) active#(from(X)) -> s#(X) active#(from(X)) -> from#(s(X)) active#(from(X)) -> cons#(X,from(s(X))) active#(from(X)) -> mark#(cons(X,from(s(X)))) mark#(2nd(X)) -> mark#(X) mark#(2nd(X)) -> 2nd#(mark(X)) mark#(2nd(X)) -> active#(2nd(mark(X))) mark#(cons(X1,X2)) -> mark#(X1) mark#(cons(X1,X2)) -> cons#(mark(X1),X2) mark#(cons(X1,X2)) -> active#(cons(mark(X1),X2)) mark#(from(X)) -> mark#(X) mark#(from(X)) -> from#(mark(X)) mark#(from(X)) -> active#(from(mark(X))) mark#(s(X)) -> mark#(X) mark#(s(X)) -> s#(mark(X)) mark#(s(X)) -> active#(s(mark(X))) 2nd#(mark(X)) -> 2nd#(X) 2nd#(active(X)) -> 2nd#(X) cons#(mark(X1),X2) -> cons#(X1,X2) cons#(X1,mark(X2)) -> cons#(X1,X2) cons#(active(X1),X2) -> cons#(X1,X2) cons#(X1,active(X2)) -> cons#(X1,X2) from#(mark(X)) -> from#(X) from#(active(X)) -> from#(X) s#(mark(X)) -> s#(X) s#(active(X)) -> s#(X) TRS: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) mark(2nd(X)) -> active(2nd(mark(X))) mark(cons(X1,X2)) -> active(cons(mark(X1),X2)) mark(from(X)) -> active(from(mark(X))) mark(s(X)) -> active(s(mark(X))) 2nd(mark(X)) -> 2nd(X) 2nd(active(X)) -> 2nd(X) cons(mark(X1),X2) -> cons(X1,X2) cons(X1,mark(X2)) -> cons(X1,X2) cons(active(X1),X2) -> cons(X1,X2) cons(X1,active(X2)) -> cons(X1,X2) from(mark(X)) -> from(X) from(active(X)) -> from(X) s(mark(X)) -> s(X) s(active(X)) -> s(X) Matrix Interpretation Processor: dim=2 usable rules: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) mark(2nd(X)) -> active(2nd(mark(X))) mark(cons(X1,X2)) -> active(cons(mark(X1),X2)) mark(from(X)) -> active(from(mark(X))) mark(s(X)) -> active(s(mark(X))) 2nd(mark(X)) -> 2nd(X) 2nd(active(X)) -> 2nd(X) cons(mark(X1),X2) -> cons(X1,X2) cons(X1,mark(X2)) -> cons(X1,X2) cons(active(X1),X2) -> cons(X1,X2) cons(X1,active(X2)) -> cons(X1,X2) from(mark(X)) -> from(X) from(active(X)) -> from(X) s(mark(X)) -> s(X) s(active(X)) -> s(X) interpretation: [2nd#](x0) = [0 1]x0 + [1], [cons#](x0, x1) = [0 1]x0 + [0 2]x1, [from#](x0) = [0 2]x0, [s#](x0) = [0 1]x0, [mark#](x0) = [2 2]x0, [active#](x0) = [1 0]x0, [1 1] [0] [s](x0) = [0 0]x0 + [1], [2 2] [3] [from](x0) = [0 0]x0 + [0], [0 0] [0] [mark](x0) = [2 2]x0 + [1], [0 0] [0] [active](x0) = [1 1]x0 + [1], [1 1] [0] [2nd](x0) = [0 0]x0 + [3], [0 0] [0 0] [0] [cons](x0, x1) = [1 1]x0 + [0 2]x1 + [1] orientation: active#(2nd(cons(X,cons(Y,Z)))) = [1 1]X + [2 2]Y + [0 4]Z + [3] >= [2 2]Y = mark#(Y) active#(from(X)) = [2 2]X + [3] >= [0 1]X = s#(X) active#(from(X)) = [2 2]X + [3] >= [2] = from#(s(X)) active#(from(X)) = [2 2]X + [3] >= [0 1]X = cons#(X,from(s(X))) active#(from(X)) = [2 2]X + [3] >= [2 2]X + [2] = mark#(cons(X,from(s(X)))) mark#(2nd(X)) = [2 2]X + [6] >= [2 2]X = mark#(X) mark#(2nd(X)) = [2 2]X + [6] >= [2 2]X + [2] = 2nd#(mark(X)) mark#(2nd(X)) = [2 2]X + [6] >= [2 2]X + [1] = active#(2nd(mark(X))) mark#(cons(X1,X2)) = [2 2]X1 + [0 4]X2 + [2] >= [2 2]X1 = mark#(X1) mark#(cons(X1,X2)) = [2 2]X1 + [0 4]X2 + [2] >= [2 2]X1 + [0 2]X2 + [1] = cons#(mark(X1),X2) mark#(cons(X1,X2)) = [2 2]X1 + [0 4]X2 + [2] >= [0] = active#(cons(mark(X1),X2)) mark#(from(X)) = [4 4]X + [6] >= [2 2]X = mark#(X) mark#(from(X)) = [4 4]X + [6] >= [4 4]X + [2] = from#(mark(X)) mark#(from(X)) = [4 4]X + [6] >= [4 4]X + [5] = active#(from(mark(X))) mark#(s(X)) = [2 2]X + [2] >= [2 2]X = mark#(X) mark#(s(X)) = [2 2]X + [2] >= [2 2]X + [1] = s#(mark(X)) mark#(s(X)) = [2 2]X + [2] >= [2 2]X + [1] = active#(s(mark(X))) 2nd#(mark(X)) = [2 2]X + [2] >= [0 1]X + [1] = 2nd#(X) 2nd#(active(X)) = [1 1]X + [2] >= [0 1]X + [1] = 2nd#(X) cons#(mark(X1),X2) = [2 2]X1 + [0 2]X2 + [1] >= [0 1]X1 + [0 2]X2 = cons#(X1,X2) cons#(X1,mark(X2)) = [0 1]X1 + [4 4]X2 + [2] >= [0 1]X1 + [0 2]X2 = cons#(X1,X2) cons#(active(X1),X2) = [1 1]X1 + [0 2]X2 + [1] >= [0 1]X1 + [0 2]X2 = cons#(X1,X2) cons#(X1,active(X2)) = [0 1]X1 + [2 2]X2 + [2] >= [0 1]X1 + [0 2]X2 = cons#(X1,X2) from#(mark(X)) = [4 4]X + [2] >= [0 2]X = from#(X) from#(active(X)) = [2 2]X + [2] >= [0 2]X = from#(X) s#(mark(X)) = [2 2]X + [1] >= [0 1]X = s#(X) s#(active(X)) = [1 1]X + [1] >= [0 1]X = s#(X) [0 0] [0 0] [0 0] [0] [0 0] [0] active(2nd(cons(X,cons(Y,Z)))) = [1 1]X + [2 2]Y + [0 4]Z + [7] >= [2 2]Y + [1] = mark(Y) [0 0] [0] [0 0] [0] active(from(X)) = [2 2]X + [4] >= [2 2]X + [3] = mark(cons(X,from(s(X)))) [0 0] [0] [0 0] [0] mark(2nd(X)) = [2 2]X + [7] >= [2 2]X + [5] = active(2nd(mark(X))) [0 0] [0 0] [0] [0 0] [0 0] [0] mark(cons(X1,X2)) = [2 2]X1 + [0 4]X2 + [3] >= [2 2]X1 + [0 2]X2 + [3] = active(cons(mark(X1),X2)) [0 0] [0] [0 0] [0] mark(from(X)) = [4 4]X + [7] >= [4 4]X + [6] = active(from(mark(X))) [0 0] [0] [0 0] [0] mark(s(X)) = [2 2]X + [3] >= [2 2]X + [3] = active(s(mark(X))) [2 2] [1] [1 1] [0] 2nd(mark(X)) = [0 0]X + [3] >= [0 0]X + [3] = 2nd(X) [1 1] [1] [1 1] [0] 2nd(active(X)) = [0 0]X + [3] >= [0 0]X + [3] = 2nd(X) [0 0] [0 0] [0] [0 0] [0 0] [0] cons(mark(X1),X2) = [2 2]X1 + [0 2]X2 + [2] >= [1 1]X1 + [0 2]X2 + [1] = cons(X1,X2) [0 0] [0 0] [0] [0 0] [0 0] [0] cons(X1,mark(X2)) = [1 1]X1 + [4 4]X2 + [3] >= [1 1]X1 + [0 2]X2 + [1] = cons(X1,X2) [0 0] [0 0] [0] [0 0] [0 0] [0] cons(active(X1),X2) = [1 1]X1 + [0 2]X2 + [2] >= [1 1]X1 + [0 2]X2 + [1] = cons(X1,X2) [0 0] [0 0] [0] [0 0] [0 0] [0] cons(X1,active(X2)) = [1 1]X1 + [2 2]X2 + [3] >= [1 1]X1 + [0 2]X2 + [1] = cons(X1,X2) [4 4] [5] [2 2] [3] from(mark(X)) = [0 0]X + [0] >= [0 0]X + [0] = from(X) [2 2] [5] [2 2] [3] from(active(X)) = [0 0]X + [0] >= [0 0]X + [0] = from(X) [2 2] [1] [1 1] [0] s(mark(X)) = [0 0]X + [1] >= [0 0]X + [1] = s(X) [1 1] [1] [1 1] [0] s(active(X)) = [0 0]X + [1] >= [0 0]X + [1] = s(X) problem: DPs: TRS: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) mark(2nd(X)) -> active(2nd(mark(X))) mark(cons(X1,X2)) -> active(cons(mark(X1),X2)) mark(from(X)) -> active(from(mark(X))) mark(s(X)) -> active(s(mark(X))) 2nd(mark(X)) -> 2nd(X) 2nd(active(X)) -> 2nd(X) cons(mark(X1),X2) -> cons(X1,X2) cons(X1,mark(X2)) -> cons(X1,X2) cons(active(X1),X2) -> cons(X1,X2) cons(X1,active(X2)) -> cons(X1,X2) from(mark(X)) -> from(X) from(active(X)) -> from(X) s(mark(X)) -> s(X) s(active(X)) -> s(X) Qed