2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153381This is the first 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 review the definitions of vertex operator algebras and twisted modules, and discuss examples.LaTeX file, 26 pagesQuantum AlgebraHigh Energy Physics - Theorytext