MAYBE
0.17/0.21	MAYBE
0.17/0.21	
0.17/0.21	Problem:
0.17/0.21	 active(from(X)) -> mark(cons(X,from(s(X))))
0.17/0.21	 active(head(cons(X,XS))) -> mark(X)
0.17/0.21	 active(2nd(cons(X,XS))) -> mark(head(XS))
0.17/0.21	 active(take(0(),XS)) -> mark(nil())
0.17/0.21	 active(take(s(N),cons(X,XS))) -> mark(cons(X,take(N,XS)))
0.17/0.21	 active(sel(0(),cons(X,XS))) -> mark(X)
0.17/0.21	 active(sel(s(N),cons(X,XS))) -> mark(sel(N,XS))
0.17/0.21	 active(from(X)) -> from(active(X))
0.17/0.21	 active(cons(X1,X2)) -> cons(active(X1),X2)
0.17/0.21	 active(s(X)) -> s(active(X))
0.17/0.21	 active(head(X)) -> head(active(X))
0.17/0.21	 active(2nd(X)) -> 2nd(active(X))
0.17/0.21	 active(take(X1,X2)) -> take(active(X1),X2)
0.17/0.21	 active(take(X1,X2)) -> take(X1,active(X2))
0.17/0.21	 active(sel(X1,X2)) -> sel(active(X1),X2)
0.17/0.21	 active(sel(X1,X2)) -> sel(X1,active(X2))
0.17/0.21	 from(mark(X)) -> mark(from(X))
0.17/0.21	 cons(mark(X1),X2) -> mark(cons(X1,X2))
0.17/0.21	 s(mark(X)) -> mark(s(X))
0.17/0.21	 head(mark(X)) -> mark(head(X))
0.17/0.21	 2nd(mark(X)) -> mark(2nd(X))
0.17/0.21	 take(mark(X1),X2) -> mark(take(X1,X2))
0.17/0.21	 take(X1,mark(X2)) -> mark(take(X1,X2))
0.17/0.21	 sel(mark(X1),X2) -> mark(sel(X1,X2))
0.17/0.21	 sel(X1,mark(X2)) -> mark(sel(X1,X2))
0.17/0.21	 proper(from(X)) -> from(proper(X))
0.17/0.21	 proper(cons(X1,X2)) -> cons(proper(X1),proper(X2))
0.17/0.21	 proper(s(X)) -> s(proper(X))
0.17/0.21	 proper(head(X)) -> head(proper(X))
0.17/0.21	 proper(2nd(X)) -> 2nd(proper(X))
0.17/0.21	 proper(take(X1,X2)) -> take(proper(X1),proper(X2))
0.17/0.21	 proper(0()) -> ok(0())
0.17/0.21	 proper(nil()) -> ok(nil())
0.17/0.21	 proper(sel(X1,X2)) -> sel(proper(X1),proper(X2))
0.17/0.21	 from(ok(X)) -> ok(from(X))
0.17/0.21	 cons(ok(X1),ok(X2)) -> ok(cons(X1,X2))
0.17/0.21	 s(ok(X)) -> ok(s(X))
0.17/0.21	 head(ok(X)) -> ok(head(X))
0.17/0.21	 2nd(ok(X)) -> ok(2nd(X))
0.17/0.21	 take(ok(X1),ok(X2)) -> ok(take(X1,X2))
0.17/0.21	 sel(ok(X1),ok(X2)) -> ok(sel(X1,X2))
0.17/0.21	 top(mark(X)) -> top(proper(X))
0.17/0.21	 top(ok(X)) -> top(active(X))
0.17/0.21	
0.17/0.21	Proof:
0.17/0.21	 Open
0.17/0.22	EOF