this proves that there's no final total and so in that case it is some sort of constructive way in which you're showing that something is not regular something does not have a DFA so yeah it does come up elsewhere I just yeah I only have so much time yeah yeah there's a whole community of people that would disagree with I mean that solving is quite an enterprise actually yeah yeah oh well I mean there are things like this so-called exponential time hypothesis is false so then for example counting independent sets if it's in sub