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CATEGORIES:Logic and Semantics Seminar (Computer Laboratory)
SUMMARY:Semigroups with low difficulty word problem - Mark
us Pfeiffer\, St Andrew's
DTSTART;TZID=Europe/London:20130426T160000
DTEND;TZID=Europe/London:20130426T170000
UID:TALK44998AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/44998
DESCRIPTION:The word problem for groups is a well-studied noti
on in\ncomputational group theory. Results of Anis
imov\, Muller and Schupp\, Lehnert\nand Schweitzer
\, Holt\, Roever\, Thomas and many more relate the
word problem and\nthe coword problem of (classes
of) groups to (classes of) formal languages\,\nfor
example regular languages and context-free langua
ges.\nIn my research I considered a natural defini
tion of the word problem and the\ncoword problem o
f semigroups.\nUsing the notions of recognisable\,
rational\, and extended rational subsets of\nmono
ids\, I extended some of the results about groups
to semigroups.\nI then defined a hierarchy of semi
groups by difficulty of their word\nproblem.\n\nIn
my talk I will give an accessible overview of the
results\, and I will show\nhow my results can be
seen in the context of logic and complexity theory
.\nI will also give a few open questions which I h
ope to answer in the near\nfuture.
LOCATION:Room FW26\, Computer Laboratory\, William Gates Bu
ilding
CONTACT:Jonathan Hayman
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