Skip Navigation

The Computer Journal 1988 31(4):325-329; doi:10.1093/comjnl/31.4.325
© 1988 by British Computer Society
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Fang, Z.
Right arrow Articles by Deogun, J. S.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Closure Properties of Certain Classes of Languages under Generalized Morphic Replication

Z. Fang1 and J. S. Deogun2

1 Computer Science Department, The Wichita State University, Wichita, KS 67208, U.S.A.
2 Computer Science Department, University of Nebraska, Lincoln, Nebraska 68588, U.S.A.

Received 1 September 1985; revised 1 February 1987

In this paper a new language operator, a generalized morphic replication, is introduced. Let {Omega} be a finite set of morphisms and reversal morphisms from {sum}* into {Delta}*, and {omega} be in {Omega}*. A morphic replicator is defined as follows: for each x in {sum}* define {omega}(x) to be h1(x) ... hm(x), where |{omega}| = m and {omega} = h1 ... hm. A generalized morphic replication extends {omega} to languages by {omega}(L) = {{omega}(x): x is in L} and to sets W of morphic replicators, where W {subseteq} {Omega}*, W(x) = {{omega}(x): {omega} is in W} and W(L) = UW(x), where the union is taken over all x in L.

It is shown that the class of languages accepted in real time by a non-deterministic reversal-bounded multitape Turing machine, the class of NP, and the class of the recursively enumerable sets, are all closed under the generalized morphic replication when the morphisms and the reversal morphisms are, respectively, linear-erasing, polynomial-erasing, and arbitrary.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.