This book constitutes the strictly refereed post-workshop proceedings of the 11th International Workshop on Computer Science Logic, CSL '97, held as the 1997 Annual Conference of the European Association on Computer Science Logic, EACSL, in Aarhus, Denmark, in August 1997.
The volume presents 26 revised full papers selected after two rounds of refereeing from initially 92 submissions; also included are four invited papers. The book addresses all current aspects of computer science logics and its applications and thus presents the state of the art in the area.

This book constitutes the refereed proceedings of the 21st International Conference on Application and Theory of Petri Nets, ICATPN 2000, held in Aarhus, Denmark, in June 2000. The 20 revised full papers presented together with four invited surveys and four presentations were carefully reviewed and selected from 57 submissions. The papers address various aspects of Petri net research and development including system design and verification, UML, compositionality, process algebras, model checking, computer networking, business process engineering, communication networks. Various classes of...