If the acceptance form does not expressly limit acceptance to its own terms, and both parties are merchants, the offeror's acceptance of the offeree's performance, though the offeree's forms contain additional or different terms, forms a contract. At this point, if the offeree's terms cannot coexist with the offeror's terms, both terms are "knocked out" and UCC gap-fillers step in. If the offeree's terms are simply additional, they will be considered part of the contract unless (a) the offeror expressly limits acceptance to the terms of the original offer, (b) the new terms materially alter the original offer, or (c) notification of objection to the new terms has already been given or is given within a reasonable time after they are promulgated by the offeree.