Category Archives: inverse semigroups

Fields and total orders are the prime objects of nice categories

A field is also a commutative ring, so it is an object in the category of commutative rings. A total order is also a partial order, so it is an object in the category of partially ordered sets. Neither are … Continue reading

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A canonical labeling technique by Brendan McKay and isomorphism testing of deterministic finite automata

A deterministic finite automaton (DFA) is a 5-tuple, , consisting of a finite set of states a finite set of input symbols a (partial) transition function an initial state a set of accept states An isomorphism between two DFAs and … Continue reading

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Algebraic characterizations of inverse semigroups and strongly regular rings

A good place to learn about inverse semigroups are Tero Harju’s Lecture Notes on Semigroups from 1996. (J.M. Howie’s, “Fundamentals of semigroup theory” from 1995 is claimed to be even better, but I can’t comment on that.) Learning about strongly … Continue reading

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