(VAR x y z )
(RULES 
        times(x, plus(y, s(z))) -> plus(times(x, plus(y, times(s(z), 0))), times(x, s(z)))
        times(x, 0) -> 0
        times(x, s(y)) -> plus(times(x, y), x)
        plus(x, 0) -> x
        plus(x, s(y)) -> s(plus(x, y))
        
)