(VAR u v x y )
(STRATEGY INNERMOST)
(RULES 
        minus(x,y) -> cond(gt(x,y),x,y)
        cond(false,x,y) -> 0
        cond(true,x,y) -> s(minus(x,s(y)))
        gt(0,v) -> false
        gt(s(u),0) -> true
        gt(s(u),s(v)) -> gt(u,v)
        
)