2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53694Ideas recently put forward by Y. Matsuo and the author are summarized on the example of the simplest ($W_3$) generalization of two-dimensional gravity. These notes are based on lectures given at the workshop `` Strings, Conformal Models and Topological Field Theories'', Cargese 12-21 May 1993; and at the meeting ``String 93'', Berkeley, 24-29 May 1993.LPTENS preprint 93/38, LATEX file 15 pagesHigh Energy Physics - Theorytext