(VAR x y )
(STRATEGY INNERMOST)
(RULES 
        p(s(x)) -> x
        fact(0) -> s(0)
        fact(s(x)) -> *(s(x),fact(p(s(x))))
        *(0,y) -> 0
        *(s(x),y) -> +(*(x,y),y)
        +(x,0) -> x
        +(x,s(y)) -> s(+(x,y))
        
)