Volume 14, Number 3, 2000

•   Klaus-Dieter Schewe, Torsten Ripke, Sven Drechsler: Hybrid Concurrency Control and Recovery for Multi-Level Transactions 419

•   Ferucio Laurentiu TIPLEA, Cristina BADARAU: A Note on Decidability of Reachability for Conditional Petri Nets 455

•   Pál Dömösi: Unusual Algorithms for Lexicographical Enumeration 461

•   Takeshi Koshiba, Erkki Mäkinen, Yuji Takada: Inferring pure context-free languages from positive data 469

•   Erkki Mäkinen: On inferring zero-reversible languages 479

•   Marek Michalik: F codes 485

•   Jovanka Pantovic: Note on the Cardinality of some Sets of Clones 491

•   B. Imreh, J. Fülöp, F. Friedler: A Note on the Equivalence of the Set Covering and Process Network Synthesis Problems 497

•   Béla Csaba: Note on the Work Function Algorithm 503

•   Zsolt Kalmár, Csaba Szepesvári, András Lorincz: Modular Reinforcement Learning: A Case Study in a Robot Domain 507