Erdős problem 596
Erdős Problem 596 (Erdős–Hajnal, [Er87]). For which graph pairs is it true that
Sources
FormalConjectures/ErdosProblems/
596.lean
Retained formal statement
Whether is Erdős–Hajnal exceptional is precisely the content of Erdős Problem 595. The finite Ramsey property holds (Folkman 1970, Nešetřil–Rödl [NeRo75]); the open part is whether every -free graph is a countable union of triangle-free graphs.
True ↔ (SimpleGraph.completeGraph (Fin 4)).IsErdosHajnalExceptional (SimpleGraph.completeGraph (Fin 3))OpenStatement only, no proof