(VAR IL L M N X X1 X2 )
(RULES 
        zeros -> cons(0, n__zeros)
        U11(tt, L) -> U12(tt, activate(L))
        U12(tt, L) -> s(length(activate(L)))
        U21(tt, IL, M, N) -> U22(tt, activate(IL), activate(M), activate(N))
        U22(tt, IL, M, N) -> U23(tt, activate(IL), activate(M), activate(N))
        U23(tt, IL, M, N) -> cons(activate(N), n__take(activate(M), activate(IL)))
        length(nil) -> 0
        length(cons(N, L)) -> U11(tt, activate(L))
        take(0, IL) -> nil
        take(s(M), cons(N, IL)) -> U21(tt, activate(IL), M, N)
        zeros -> n__zeros
        take(X1, X2) -> n__take(X1, X2)
        activate(n__zeros) -> zeros
        activate(n__take(X1, X2)) -> take(X1, X2)
        activate(X) -> X
        
)