2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153382This is the second part of the revised versions of the notes of three consecutive expository lectures given by Chongying Dong, Haisheng Li and Yi-Zhi Huang in the conference on Monster and vertex operator algebras at the Research Institute of Mathematical Sciences, Kyoto, September 4-9, 1994. In this part, we discuss the commutativity, the associativity, the Jacobi identity and the relations among them. We also discuss an analogue of endomorphism ring of a vector space in vertex operator algebra theory.LeTeX file, 27 pagesQuantum AlgebraHigh Energy Physics - Theorytext