Inkdot versus Pebble over Two-Dimensional Languages

Atsuyuki INOUE  Akira ITO  Kunihiko HIRAISHI  Katsushi INOUE 

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences  Vol.E88-A  No.5  pp.1173-1180
Publication Date: 2005/05/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
inkdot,  pebble,  two-dimensional automata,  nondeterminism,  alternation, 

Full Text: PDF

Summary: 
This paper investigates a relationship between inkdot and one-pebble for two-dimensional finite automata (2-fa's). Especially we show that (1) alternating inkdot 2-fa's are more powerful than nondeterministic one-pebble 2-fa's, and (2) there is a set accepted by an alternating inkdot 2-fa, but not accepted by any alternating one-pebble 2-fa with only universal states.