This volume contains the proceedings of CONCUR '93, thefourth in an annual series of conferences devoted to thestudy of concurrency. The basic aim of the CONCURconferences is to communicate advances in concurrency theoryand applications.The volume contains 31 papers selected from 113submissions,together with four invited papers and two abstracts ofinvited talks. The invited talks are: "The lambda-calculuswith multiplicities" (extended abstract) by G rard Boudol,"A pi-calculus semantics for an object-based designnotation" by Cliff B. Jones, "Partial-order methods fortemporal verification" by Pierre Wolper and PatriceGodefroid, "Non-interleaving process algebra" by Jos C.M.Baetenand Jan A. Bergstra, "Loop parallelization in thepolytope model" by Christian Lengauer, and "Structuredoperational semantics for process algebras and equationalaxiom systems" (abstract) by Bard Bloom.
