(STRATEGY
    INNERMOST)

(VAR
    u v x y)
(DATATYPES
    A = µX.< s(X), false, 0, true >)
(SIGNATURES
    minus :: [A x A] -> A
    cond :: [A x A x A] -> A
    ge :: [A x A] -> A)
(RULES
    minus(x,y) -> cond(ge(x,s(y))
                      ,x
                      ,y)
    cond(false(),x,y) -> 0()
    cond(true(),x,y) -> s(minus(x
                               ,s(y)))
    ge(u,0()) -> true()
    ge(0(),s(v)) -> false()
    ge(s(u),s(v)) -> ge(u,v))