Wikipedia · textbook · AMS 5

mediumknown result, no worker yet

Conway's 99-graph problem

Theorem · completeGraphIsClique

A finset of vertices in a complete graph is always a clique.

Formal statement · Lean 4.lean
lemma completeGraphIsClique (s : Finset V) : (⊤ : SimpleGraph V).IsClique s := by
  sorry

Proof. sorry

Nobody has tried yet.

Reference ↗ · Lean source ↗