(VAR x y )
(RULES 
        f(true,x,y) -> f(gt(x,y),double(x),s(y))
        gt(s(x),0) -> true
        gt(0,y) -> false
        gt(s(x),s(y)) -> gt(x,y)
        double(0) -> 0
        double(s(x)) -> s(s(double(x)))
        
)