(VAR X X1 X2 Y Z )
(RULES 
        active(2nd(cons1(X, cons(Y, Z)))) -> mark(Y)
        active(2nd(cons(X, X1))) -> mark(2nd(cons1(X, X1)))
        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))
        active(cons1(X1, X2)) -> cons1(active(X1), X2)
        active(cons1(X1, X2)) -> cons1(X1, active(X2))
        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))
        cons1(mark(X1), X2) -> mark(cons1(X1, X2))
        cons1(X1, mark(X2)) -> mark(cons1(X1, X2))
        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))
        proper(cons1(X1, X2)) -> cons1(proper(X1), proper(X2))
        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))
        cons1(ok(X1), ok(X2)) -> ok(cons1(X1, X2))
        top(mark(X)) -> top(proper(X))
        top(ok(X)) -> top(active(X))
        
)