4 papers · 1 filter
Word problem languages for completely regular semigroups
Tara Brough
Motivated by the question of which completely regular semigroups have context-free word problem, we show that for certain classes of languages (including context-free…
Context-free word problem semigroups
Tara Brough, Alan J. Cain, Markus Pfeiffer
This paper studies the classes of semigoups and monoids with context-free and deterministic context-free word problem. First, some examples are exhibited to clarify the relationshi…
Word Problem Languages for Free Inverse Monoids
Tara Brough
This paper considers the word problem for free inverse monoids of finite rank from a language theory perspective. It is shown that no free inverse monoid has context-free word prob…
Two applications of monoid actions to cross-sections
Tara Brough, Alan J. Cain, Victor Maltcev
Using a construction that builds a monoid from a monoid action, this paper exhibits an example of a direct product of monoids that admits a prefix-closed regular cross-section, but…