Publications
A counterexample to a conjecture concerning concatenation hierarchies. Inform. Process. Lett.. 2009;110:4-7.Edit
On Decidability of Intermediate Levels of Concatenation Hierarchies. In: 19th International Conference Developments in Language Theory (DLT 2015). Vol Developments in Language Theory, LNCS 9168. UK, Liverpool: Springer; 2015. 5. p. 58-70p. Edit
On fixed points of the lower set operator. Int. J. Algebra Comput.. 2015;25(1-2):259-292.Edit
[2017-25] On the insertion of n-powers .Edit
On the irreducibility of pseudovarieties of semigroups. Journal of Pure and Applied Algebra. 2016;220(4):1517-1524.Edit
[2009-39] New decidable upper bound of the second level in the Straubing-Thérien concatenation hierarchy .Edit
New decidable upper bound of the second level in the Straubing-Thérien concatenation hierarchy of star-free languages. Discrete Math. Theor. Comput. Sci.. 2010;12:41-58.Edit
Reducibility vs. definability for pseudovarieties of semigroups. International Journal of Algebra and Computation. 2016;26(7):1483-1495.Edit
[2017-9] Towards a pseudoequational proof theory .Edit
The ω-inequality problem for concatenation hierarchies of star-free languages. Forum Mathematicum. 2018;30:663-679.Edit