2018/05/08 by Brough, Tara, Cain, Alan J.
#03D40 #08A50 #20F10 #20M05 #68Q45 #FOS: Computer and information sciences #FOS: Mathematics #Formal Languages and Automata Theory (cs.FL) #Group Theory (math.GR)
paper · doi:10.48550/arxiv.1805.03125
Motivated by the study of word problems of monoids, we explore two ways of viewing binary relations on A^* as languages. We exhibit a hierarchy of classes of binary relations on A^*, according to the class of languages the relation belongs to and the chosen viewpoint. We give examples of word problems of monoids distinguishing the various classes.