Regular Section
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PAPERS
======
[Automata, Language and Theory of Computing]

 . Asynchronous and Synchronous Parallel Derivation of Formal Languages
            ........................................................ 539
        Katsuhiko NAKAMURA

[Algorithm and Computational Complexity]

 . A Task Mapping Algorithm for Linear Array Processors ............ 546
        Tsuyoshi KAWAGUCHI, Yoshinori TAMURA and Kouichi UTSUMIYA

 . A Metric between Unrooted and Unordered Trees and Its Top-down
   Computing Method ................................................ 555
        Tomokazu MUGURUMA, Eiichi TANAKA and Sumio MASUDA

[Computer Hardware and Design]

 . On a Class of Multiple-Valued Logic Functions with Truncated Sum,
   Differential Product and Not Operations ......................... 567
        Yutaka HATA and Kazuharu YAMATO

[Computer Systems]

 . A Design and Implementation of an Ada IPC Interface ............. 574
        Masahiro NAKAMA and Zensho NAKAO

 . Parallel Implementations of Back Propagation Networks on a Dynamic
   Data-Driven Multiprocessor ...................................... 579
        Ali M.ALHAJ and Hiroaki TERADA

[Software Theory]

 . A Parallel Quicksort in Ada and Its Performance Profile ......... 589
        Zensho NAKAO

LETTERS
=======
[Automata, Language and Theory of Computing]

 . The Emptiness Problem for Lexical-Functional Grammars is Undecidable
            ........................................................ 597
        Tetsuro NISHINO

[Computer Networks]

 . A New Method for Lock Waiting in Mutual-Exclusions .............. 601
        Koichiro ISHIHARA, Kazuyoshi NEGISHI and Tetsuhiko FUJII

 . ABSTRACTS (Trans.IEICE, Vol.J77-D-‡T, J77-D-‡U, No.5 in Japanese)
            ........................................................ 605