Abstract

We introduce the notion of a deterministic biautomaton, a device that reads inputs from both ends, and admits at most one computation on every input word. We show that deterministic biautomata recognize a class of languages which is properly included in the class of linear languages, and which is incomparable to the class of languages recognized by deterministic one-turn pushdown automata. We propose three restrictions of the basic model of deterministic biautomata to characterize the classes of languages generated by DL, linear LL(1), and NH-DL grammars. This results in a chain of four subclasses of linear languages in which all inclusions are strict. For these subclasses and basic operations, we show whether or not a particular class is closed under a considered operation. We prove that it is undecidable whether a linear language belongs to any of these four classes and answer some other decidability questions.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.