The issue is that law, especially contract law, very often turns on the minutiae of what specifically was intended by a given statement in text. That's why cont

The issue is that law, especially contract law, very often turns on the minutiae of what specifically was intended by a given statement in text. That's why contracts have pages and pages of definitions that seem obvious, and why courts assign special meanings to terms like "irrevocable". That is to say, at some point in the past, some court case probably turned on proving that "irrevocable" was supposed to mean something different than "perpetual," and so now the standard is to assume that's what it means, unless the contract explicitly says something different. What if I want a contract that I can't choose to take back, but which doesn't last forever? It's a problem of trying to force precision on a language that is inherently imprecise, topped off with concepts that are actually hard to understand.