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