(VAR x y z )
(RULES 
        div(0, y) -> 0
        div(x, y) -> quot(x, y, y)
        quot(0, s(y), z) -> 0
        quot(s(x), s(y), z) -> quot(x, y, z)
        quot(x, 0, s(z)) -> s(div(x, s(z)))
        
)