I came across this type of clause, and found that it's quite common. I understand the part that says an agreement supersedes any previous agreements, but the clause looks something like this:
Supersedes Previous Agreements. This Agreement supersedes all prior or contemporaneous negotiations, commitments, agreements and writings with respect to the subject matter hereof, all such other negotiations, commitments, agreements and writings will have no further force or effect, and the parties to any such other negotiation, commitment, agreement or writing will have no further rights or obligations thereunder.
I understand that a new agreement can supersede an older one. All that needs to be done in that case is to establish the time that any other ones were made, and by comparison you can know that one in particular is the latest one. But I don't understand how an agreement can supersede all over contemporaneous agreements. I understand "contemporaneous" to mean at the same time, am I wrong about that? Is it even possible for two separate agreements to be made exactly contemporaneously? Also what happens if other agreements have this clause (that it supersedes all other agreements)? If it is possible for multiple agreements to be made exactly contemporaneously (which I take to mean exactly at the same time, which I'm not sure is possible), doesn't this result in multiple agreements superseding each other?