a1 Department of Mathematics and Turku Centre for Computer Science, University of Turku, FIN-20014 Turku, Finland; email@example.com; firstname.lastname@example.org; email@example.com
We consider relational periods, where the relation is a compatibility relation on words induced by a relation on letters. We prove a variant of the theorem of Fine and Wilf for a (pure) period and a relational period.
(Received April 18 2007)
(Accepted April 29 2008)
(Online publication June 5 2008)
Mathematics Subject Classification: