Why is the definite article used in this sentence?
An alternative in international commercial arbitration (whether or not the underlying dispute relates to construction) is for the parties to agree that the tribunal can appoint the expert or experts.
Shouldn't the indefinite article be used here? Or is "the expert" referring to some idealized abstract generic expert, so to speak? The word "experts" surely isn't, because there is no article at all before it.
P.S. I've also seen this construction (e.g. "the X or X's" where X is a noun) used with nouns other than "expert" a few times.