Ambiguity in omega context free languages

Olivier Finkel
2003 Theoretical Computer Science  
We extend the well-known notions of ambiguity and of degrees of ambiguity of ÿnitary context free languages to the case of omega context free languages (!-CFL) accepted by B uchi or Muller pushdown automata. We show that these notions may be deÿned independently of the B uchi or Muller acceptance condition which is considered. We investigate ÿrst properties of the subclasses of omega context free languages we get in that way, giving many examples and studying topological properties of !-CFL of
more » ... given degree of ambiguity. (O. Finkel). 0304-3975/03/$ -see front matter c 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 0 4 -3 9 7 5 ( 0 2 ) 0 0 5 8 4 -4
doi:10.1016/s0304-3975(02)00584-4 fatcat:zohu57u5t5dzrh6yjhpiqdf2pe