(STRATEGY
    INNERMOST)

(VAR
    x y)
(DATATYPES
    A = µX.< 0, false, s(X), true, and(X, X), not(X), =(X, X), rem(X, X) >)
(SIGNATURES
    prime :: [A] -> A
    prime1 :: [A x A] -> A
    divp :: [A x A] -> A)
(RULES
    prime(0()) -> false()
    prime(s(0())) -> false()
    prime(s(s(x))) -> prime1(s(s(x))
                            ,s(x))
    prime1(x,0()) -> false()
    prime1(x,s(0())) -> true()
    prime1(x,s(s(y))) ->
      and(not(divp(s(s(y)),x))
         ,prime1(x,s(y)))
    divp(x,y) -> =(rem(x,y),0()))