(VAR X X1 Y Z )
(RULES 
        2nd(cons1(X, cons(Y, Z))) -> Y
        2nd(cons(X, X1)) -> 2nd(cons1(X, activate(X1)))
        from(X) -> cons(X, n__from(n__s(X)))
        from(X) -> n__from(X)
        s(X) -> n__s(X)
        activate(n__from(X)) -> from(activate(X))
        activate(n__s(X)) -> s(activate(X))
        activate(X) -> X
        
)