MULTI-PUSH-DOWN LANGUAGES AND GRAMMARS

LUCA BREVEGLIERI, ALESSANDRA CHERUBINI, CLAUDIO CITRINI, STEFANO CRESPI REGHIZZI
1996 International Journal of Foundations of Computer Science  
A new class of languages, called multi-push-down (mpd), that generalize the classical context-free (cf, or Chomsky type 2) ones is introduced. These languages preserve some important properties of cf languages: a generalization of the Chomsky-Sch utzenberger homomorphic characterization theorem, the Parikh theorem and a \pumping lemma" are proved. Multi-push-down languages are an AFL. Their recognizers are automata equipped with a multi-push-down tape. Multi-push-down languages form a hierarchy based on the number of push-down tapes.
doi:10.1142/s0129054196000191 fatcat:iou2glwgnjecpejuxj3lfk5yre