Publications
An addendum: ``The gap between partial and full'' [Internat. J. Algebra Comput. \bf 8 (1998), no. 3, 399–430; MR1627844 (99g:20102)]. Internat. J. Algebra Comput.. 2001;11:131-135.Edit
The algebra of implicit operations. Algebra Universalis. 1989;26:16-32.Edit
An automata-theoretic approach to the word problem for ω-terms over $\ssfR$. Theoret. Comput. Sci.. 2007;370:131-169.Edit
Characterization of group radicals with an application to Mal\cprime cev products. Illinois J. Math.. 2010;54:199-221.Edit
A classification of aperiodic power monoids. J. Algebra. 1994;170:355-387.Edit
Closures of regular languages for profinite topologies. Semigroup Forum. 2014;89:20-40.Edit
Commutative positive varieties of languages. Acta Cybernetica. 2017;23(1):91-111.Edit
Complete kappa-reducibility of pseudovarieties of the form DRH. International Journal of Algebra and Computation. 2017;27(02):189-236.Edit
Complete reducibility of systems of equations with respect to $\ssf R$. Port. Math. (N.S.). 2007;64:445-508.Edit
Complete κ-reducibility of pseudovarieties of the form DRH. International Journal of Algebra and Computation. 2017;27(2):189-235.Edit
Complexity of the identity checking problem for finite semigroups. Zap. Nauchn. Sem. S.-Peterburg. Otdel. Mat. Inst. Steklov. (POMI). 2008;358:5-22, 301.Edit
A counterexample to a conjecture concerning concatenation hierarchies. Inform. Process. Lett.. 2009;110:4-7.Edit
Decidability and tameness in the theory of finite semigroups. Bull. Iranian Math. Soc.. 2008;34:1-22.Edit
On the decidability of iterated semidirect products with applications to complexity. Proc. London Math. Soc. (3). 2000;80:50-74.Edit
Description and analysis of a bottom-up DFA minimization algorithm. Inform. Process. Lett.. 2008;107:52-59.Edit
On direct product decompositions of finite $\scr J$-trivial semigroups. Internat. J. Algebra Comput.. 1991;1:329-337.Edit
Dynamics of implicit operations and tameness of pseudovarieties of groups. Trans. Amer. Math. Soc.. 2002;354:387-411 (electronic).Edit
An elementary proof that finite groups are projectively torsion-free. Portugal. Math.. 1990;47:437-444.Edit
On the equation $\bf V\ast\bf G=\scr E\,\bf V$. J. Pure Appl. Algebra. 2002;166:1-28.Edit
Equidivisible pseudovarieties of semigroups. Publicationes Mathematicae. 2017;90(3-4):435-453.Edit
Factoriality and the Pin-Reutenauer procedure. Discrete Math. Theor. Comput. Sci.. 2016;18:Paper No. 1, 23.Edit
On finite simple semigroups. Proc. Edinburgh Math. Soc. (2). 1991;34:205-215.Edit
On finitely based pseudovarieties of the form $\bf V\ast\bf D$ and $\bf V\ast\bf D_n$. J. Pure Appl. Algebra. 2000;146:1-15.Edit
On fixed points of the lower set operator. Int. J. Algebra Comput.. 2015;25(1-2):259-292.Edit
Free profinite $\scr R$-trivial monoids. Internat. J. Algebra Comput.. 1997;7:625-671.Edit