Discussion

1. The (im)possibility of constructively building a switching i-component of a binary completely regular code is discussed (rep. D.S.Krotov). 2. The Hoffman bound on the maximum size of an independent set in a regular graph in terms of the minimum eigenvalue is discussed (rep. V.N.Potapov). 3. It is reported about a maximum independent set in a generalized Petersen graphs with pentagons (rep. S.V.Avgustinovich).