3.3 \(k = 4\)
Theorem conjecture_5_10_at_k4 (N : nat) : exists T : tournament, kcritical 4 T /\ (N < #|T|)%N.
Source: theories/applications/k4/k4_main.v:74
Decoded. As for \(k = 3\), with witness \(\mathrm{AC}_n[C_3]\) on \(3n\) vertices (2.19; the underlying values \(\bar\omega = 4\), \(\bar\omega (T - v) = 3\) are 4.7, 4.8).
Theorem question_5_9_fails_at_k4 (L : nat) :
exists T : tournament,
[/\ kcritical 4 T, (L < #|T|)%N
& forall S : {set T}, (4 <= ω̄(sub_tournament S))%N -> S = [set: T]].