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