(VAR x y )
(RULES 
        minus(x, 0) -> x
        minus(s(x), s(y)) -> minus(x, y)
        le(0, y) -> true
        le(s(x), 0) -> false
        le(s(x), s(y)) -> le(x, y)
        quot(x, s(y)) -> if_quot(le(s(y), x), x, s(y))
        if_quot(true, x, y) -> s(quot(minus(x, y), y))
        if_quot(false, x, y) -> 0
        
)