How is it irrelevant to this discussion? Parent proposed that aliens will have zero by posing that question. I gave an example from our own earth indicating intelligent life can manage without zero.
>They won't have a concept of zero? They won't have a concept of 1=successor(0)? I find this very, very hard to believe
Most of the world did mathematics for a long time without zero (I hope you know that most number systems like Roman didn't have zero till that eventually came from India, and we evolved to have the current number system).
Who knows what direction different number systems might have taken if they didn't come in contact with zero.