1 citations · 2 across the 6 of their papers we have counts for
6 papers
Pointlike sets with respect to ER
Karsten Henckell, Samuel Herman
We show that pointlike sets are decidable for the pseudovariety of finite semigroups whose idempotent-generated subsemigroup is R-trivial. Notably, our proof is constructive: we pr…
Product Expansions Redux
Karsten Henckell, Samuel Herman
We introduce a generalization of the product expansion of a finite semigroup. As an application, we provide an alternative proof of the decidability of pointlike sets for pseudovar…
A General Theory of Pointlike Sets
Karsten Henckell, Samuel Herman
We introduce a general unifying framework for the investigation of pointlike sets. The pointlike functors are considered as distinguished elements of a certain lattice of subfuncto…
An Effective Lower Bound for Group Complexity of Finite Semigroups and Automata
Karsten Henckell, John Rhodes, Benjamin Steinberg
The question of computing the group complexity of finite semigroups and automata was first posed in K. Krohn and J. Rhodes, \textit{Complexity of finite semigroups}, Annals of Math…
Aperiodic Pointlikes and Beyond
Karsten Henckell, John Rhodes, Benjamin Steinberg
We prove that if is a recursive set of primes, then pointlike sets are decidable for the pseudovariety of semigroups whose subgroups are -groups. In particular, when is…
A Profinite Approach to Stable Pairs
Karsten Henckell, John Rhodes, Benjamin Steinberg
We give a short proof, using profinite techniques, that idempotent pointlikes, stable pairs and triples are decidable for the pseudovariety of aperiodic monoids. Stable pairs are a…