Free submonoids and minimal

 -generators of

  Igor Litovsky

Abstract:

  Let be an alphabet and let be a language in . An -generator of is a language such that . The language Stab is a submonoid of . We give results concerning the -generators for the case when is a free submonoid which are not available in the general case. In particular, we prove that every -generator of contains at least one minimal -generator of . Furthermore these minimal -generators are codes We also characterize the -languages having only finite languages as minimal -generators. Finally, we characterize the -languages -generated by finite prefix codes.

 Gyenizse Pal 1996. Szeptember 4. Szerda 14:11:25 MET DST