(VAR x y) (THEORY (AC plus) (AC mult)) (RULES zero(sharp) -> sharp plus(x, sharp) -> x plus(zero(x), zero(y)) -> zero(plus(x,y)) plus(zero(x), one(y)) -> one(plus(x,y)) plus(one(x), one(y)) -> zero(plus(x,plus(y, one(sharp)))) mult(x, sharp) -> sharp mult(zero(x), y) -> zero(mult(x, y)) mult(one(x), y) -> plus(zero(mult(x, y)), y) )