I forgot to mention that I like your idea. And yeah, semantics and computing are related in a complex way, but certainly are not the same thing.

I was distracted, trying to think of where I'd seen something like that in science fiction, and now I think (but can't check right now) that Robert Heinlein's novelette "Gulf" had something about the smallest unit of thought; the "psychon" or some such.

There may also have been something in Keith Laumer's "The Great Time Machine Hoax", but I'm less sure about that.