16 citations · 36 across the 11 of their papers we have counts for
17 papers
Free inverse monoids are co-context-free
Tara Macalister Brough, Marianne Johnson, Mark Kambites +1
We prove (using grammars) that the free inverse monoid of every finite rank has co-context-free word problem. Equivalently, the co-word problem of the free inverse monoid of every…
Every numerical semigroup arises as an automaton monoid
Tara Macalister Brough, Alan J. Cain, Jan Philipp Wächter
This paper shows how to construct explicitly an automaton that generates an arbitrary numerical semigroup.
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…
Preserving self-similarity in free products of semigroups
Tara Macalister Brough, Jan Philipp Wächter, Janette Welker
We improve on earlier results on the closure under free products of the class of automaton semigroups. We consider partial automata and show that the free product of two self-simil…
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…
A Language Hierarchy of Binary Relations
Tara Brough, Alan J. Cain
Motivated by the study of word problems of monoids, we explore two ways of viewing binary relations on as languages. We exhibit a hierarchy of classes of binary relations on…