(VAR x y )
(STRATEGY INNERMOST)
(RULES 
        fac(0) -> 1
        fac(s(x)) -> *(s(x),fac(x))
        floop(0,y) -> y
        floop(s(x),y) -> floop(x,*(s(x),y))
        *(x,0) -> 0
        *(x,s(y)) -> +(*(x,y),x)
        +(x,0) -> x
        +(x,s(y)) -> s(+(x,y))
        1 -> s(0)
        fac(0) -> s(0)
        
)