Althoug h the class of graph algebras does not constitute a variety (as it is not c losed under direct products), it makes perfect sense to consider the satisf action relation between graphs (that is, graph algebras) and identities in the language of groupoids. Accordingly, the equational classes of graphs ar e called graph varieties. Graph varieties have been investigated by several authors. For example, Kiss, Pöschel and Pröhle determined the identities s atified by all graphs. Poomsa-ard and his coauthors have characterized the graph varieties axiomatized by the transitive and the left or right self-di stributive identities.

Continuing this line of research, we determ ined the graph varieties axiomatized by certain groupoid identities that ar e of general interest in algebra, such as the medial, (left or right) semim edial, idempotent, unipotent, zeropotent, and alternative identities.

< br/>This is joint work with Chaowat Manyuen (Khon Kaen University). DTSTAMP:20200402T184709Z DTSTART;TZID=Europe/Budapest:20180926T100000 DTEND;TZID=Europe/Budapest:20180926T120000 SEQUENCE:0 TRANSP:OPAQUE END:VEVENT END:VCALENDAR