Glasgow Mathematical Journal

Table of Contents - 2001 - Volume 43, Issue 01  


Hyperdecidability of pseudovarieties of orthogroups

Jorge Almeida a1 1 and Peter G. Trotter a2
a1 Centro de Matemática da Universidade do Porto, P. Gomes Teixeira, 4099-002 Porto, Portugal e-mail:jalmeida@fc.up.pt
a2 Department of Mathematics, University of Tasmania, GPO Box 252-37 Hobart, Tasmania 7001, Australia e-mail:trotter@hilbert.maths.edu.au

Let W denote the intersection with the pseudovariety of completely regular semigroups of the Mal'cev product of the pseudovariety of bands with a pseudovariety V of completely regular semigroups. It is shown that the (pseudo)word problem for W is reduced to that for V in such a way that decidability is preserved in the case in which terms involving only multiplication and weak inversion are considered. It is also shown that, if V is a hyperdecidable (respectively canonically reducible) pseudovariety of groups, then so is W.

(Received April 29 1999)


Footnotes

1 The first author gratefully acknowledges support by FCT through the Centro de Matemática da Universidade do Porto, by the project Praxis/2/2.1/MAT/63/94, and by the Department of Mathematics of the University of Tasmania.