[kba]

My experience is with OT, so I can't speak for CRDT, but I can imagine it's similar.

With OT, you send a na[1] (number add) operation, so this would work fine. Indeed, if you treat the number as a string, then you have a problem.

[1]: https://github.com/ottypes/json0#summary-of-operations

[taeric]

This doesn't compose with all operations. One users adds and another user multiplies, for example. That is to say, not all operations are associative.

I bet you can run really far with this general idea. But there is no panacea.

[kba]

You're absolutely right, but I'd also never suggest a collaborative system for anything critical. As I've said earlier in this thread: If you're in a Google Docs document with a buddy and you write "A" and he writes "B" at the same time, you also don't know whether that'll show up as "AB" or "BA". In practice, this isn't an issue.