fix(ErdosProblems/659): make asymptotic

[mo271]

No description provided.

[CoolRmal]

I just notice this PR and I'll close mine. I think we need to change ∀ n into ∀ n ≥ 4 (as the problem only makes sense for n ≥ 4). If we don't add this requirement, then one can prove the opposite by taking the advantage of the fact that a 0 is an empty set and thus 3 ≤ minimalDistinctDistancesSubsetOfSize (a 0) 4 = 0.

[YaelDillies]

You're right. The issue ultimately is that 3 ≤ minimalDistinctDistancesSubsetOfSize (a n) 4 doesn't mean "every subset of $4$ points determines at least $3$ distances" if a n has size at most three. Let me fix this

[callesonne]

LGTM!