This proceedings contains fourteen papers on process algebras presented at the First North American Process Algebra Workshop, held on 28 August 1992 in Stony Brook, New York. NAPAW was held in conjunc tion with CONCUR 92. It is hoped that NAPAW will be held yearly to bring together researchers from the North American continent interested in process algebras. We would like to thank the program committee members for reading through the abstracts, and Scott Smolka whose encouragement and assistance was critical to the success of the workshop. November 1992 S. Purushothaman University Park, PA Amy Zwarico Baltimore, MD Program Committee Rance Cleaveland, North Carolina State University Richard Gerber, University of Maryland at College Park Faron Moller, University of Edinburgh S. Purushothaman, Pennsylvania State University Amy Zwarico, Johns Hopkins University Contents Session 1 Real-Time Calculi and Expansion Theorems (Extended Abstract) J. C. Godskesen and K. G. Larsen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Modal Logics in Timed Process Algebras L. Brim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Process Communication Environment D. P. Gruska andA. Maggiolo-Schettini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Session 2 A Process Calculus with Incomparable Priorities H. Hansson and F. Orava . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 CCSR 92: Calculus for Communicating Shared Resources with Dynamic Priorities P. Bremond-Gregoire, S. Davidson and I. Lee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Exception Handling in Process Algebra F. S. de Boer, J. Coenen and R. Gerth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Session 3 Observation Trees (Extended Abstract) P. Degano, R. De Nicola and U. Montanari. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Computing Ready Simulations Efficiently B. Bloom and R. Paige . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Verification of Value-Passing Systems Z. Schreiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inhalt
Session 1.- Real-Time Calculi and Expansion Theorems (Extended Abstract).- Modal Logics in Timed Process Algebras.- Process Communication Environment.- Session 2.- A Process Calculus with Incomparable Priorities.- CCSR 92: Calculus for Communicating Shared Resources with Dynamic Priorities.- Exception Handling in Process Algebra.- Session 3.- Observation Trees (Extended Abstract).- Computing Ready Simulations Efficiently.- Verification of Value-Passing Systems.- An Extension of the Testing Method for Processes Passing Infinite Values.- Session 4.- Constructive Semantics.- A Causality-based Semantics for CCS.- A ?-calculus Semantics of Logical Variables and Unification.- The Total Order Assumption.- Author Index.