YES (THEORY (AC + * ) ) (VAR x2 x1 x3 x y z ) (RULES *(x2,+(x1,x3)) -> +(*(x1,x2) ,*(x3,x2)) *(s(x2),x1) -> +(*(x1,x2),x1) +(s(x2),x1) -> s(+(x1,x2)) -(s(x),s(y)) -> -(x,y) *(x,zero()) -> zero() +(x,zero()) -> x -(zero(),x) -> zero() -(x,zero()) -> x +(zero(),x1) -> x1 *(zero(),x1) -> zero() +(x,s(y)) -> s(+(x,y)) *(x,s(y)) -> +(*(x,y),x) *(+(x,y),z) -> +(*(x,z),*(y,z)) )