(STRATEGY
    INNERMOST)

(VAR
    x y)
(DATATYPES
    A = µX.< 0, s(X), true, false >)
(SIGNATURES
    p :: [A] -> A
    le :: [A x A] -> A
    minus :: [A x A] -> A
    if :: [A x A x A] -> A)
(RULES
    p(0()) -> s(s(0()))
    p(s(x)) -> x
    p(p(s(x))) -> p(x)
    le(p(s(x)),x) -> le(x,x)
    le(0(),y) -> true()
    le(s(x),0()) -> false()
    le(s(x),s(y)) -> le(x,y)
    minus(x,y) -> if(le(x,y),x,y)
    if(true(),x,y) -> 0()
    if(false(),x,y) -> s(minus(p(x)
                              ,y)))