Homomorphisms preserving types of density

The concept of density in a free monoid can be generalized from the infix relation to arbitrary relations. Many of the properties known for density can be established over these more general notions of densities. In this paper, we investigate homomorphisms which preserve different types of density....

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerzők: Jürgensen Helmut
McQuillan Ian
Testületi szerző: International Conference on Automata and Formal Languages (12.) (2008) (Szeged)
Dokumentumtípus: Cikk
Megjelent: 2009
Sorozat:Acta cybernetica 19 No. 2
Kulcsszavak:Számítástechnika, Kibernetika
Tárgyszavak:
Online Access:http://acta.bibl.u-szeged.hu/12876
Leíró adatok
Tartalmi kivonat:The concept of density in a free monoid can be generalized from the infix relation to arbitrary relations. Many of the properties known for density can be established over these more general notions of densities. In this paper, we investigate homomorphisms which preserve different types of density. We demonstrate a strict hierarchy between families of homomorphisms which preserve density over different types of relations. However, as with the case of endomorphisms, a similar hierarchy for weak-coding homomorphisms collapses. We also present an algorithm to decide whether a homomorphism preserves density over any relation which satisfies some natural conditions.
Terjedelem/Fizikai jellemzők:499-516
ISSN:0324-721X