## David Easdown (University of Sydney)
## Friday 12th May, 12.05-12.55pm, Carslaw 159## Bosets and fundamental semigroups
No, that is not a misprint! The term
A Brad Roberts (2005) has produced a large class of (nonregular) fundamental semigroups built from bosets, substantially enlarging the class explained by Nambooripad's theory (in the regular case). Roberts' construction involves a novel representation by transformations and dual transformations of certain quotients associated with equivalence relations on the underlying boset. As well as introducing Roberts' construction, the talk will illustrate bosets through examples and discuss the free semigroup on a boset, which is a key ingredient in the abstract characterisation (in the 1980s) of systems of idempotents of semigroups. Very little is known about this wild and intriguing object! |