But I'd say we don't have any example neither: regimes from your history books weren't "communism" we find in your philosophy books. You can see it if you read both carefully enough.
(and again, I'm not stating communism can work, because we don't know that).
But even if we assume both "communisms" are the same: you are saying "Communism has failed N times, therefore it will always fail". You don't know that (though I would admit it's quite solid evidence in this case)
We don't know. And I'm not arguing for or against communism here neither.
So would you agree with the statement that all attempts failed?
You see, you're mockingly presenting me as simply going "never happened therefore can't happen". I would say that you're the extreme opposite where you're going "what happened doesn't matter, we learned nothing from it".
You know, we can reason about the future past the data...? There's a reason why communism failed all attempts. That reason is something which apparently you're missing, but I'm using to support my prediction that it can't work.
I'm sorry I was not clear enough, but I'm afraid I won't be able to express myself better so I'll just leave it at that.
You are free to make this point if you want, just don't make it look like it comes from me because it doesn't.