(STRATEGY
    INNERMOST)

(VAR
    X Y Z)
(DATATYPES
    A = µX.< 0, nil, s(X), cons(X, X) >)
(SIGNATURES
    first :: [A x A] -> A
    from :: [A] -> A)
(RULES
    first(0(),X) -> nil()
    first(s(X),cons(Y,Z)) -> cons(Y
                                 ,first(X,Z))
    from(X) -> cons(X,from(s(X))))