This book constitutes the refereed proceedings of the 13th International Conference on Rewriting Techniques and Applications, RTA 2002, held in Copenhagen, Denmark, in July 2002.The 20 regular papers, two application papers, and four system descriptions presented together with three invited contributions were carefully reviewed and selected from 49 submissions. All current aspects of rewriting are addressed.

STACS, the SymposiumonTheoreticalAspects ofComputerScience, isheld- nually, alternating between France and Germany. STACS is organizedjointly by the Special Interest Group for Theoretical Computer Science of the Gesellschaft f] ur Informatik (GI) in Germany and the Maison de l'Informatique et des Ma- ematiquesDiscr etes(MIMD)inFrance.STACS2000wasthe17thintheseries.It was held in Lille from February 17th to 19th, 2000. Previous STACS symposia took place in Paris (1984), Saarbru ]cken (1985), Orsay (1986), Passau (1987), Bordeaux (1988), Paderborn (1989), Rouen (1990), Hamburg (1991), Cachan (1992), Wu ]rzburg(1993), Caen(1994), Mu ]nchen(1995), Grenoble(1996), Lub ] eck (1997), Paris (1998), and Trier (1999). All STACS proceedings have been p- lished in the Lecture Notes in Computer Science of Springer-Verlag. STACS has become one of the most important annual meetings in Europe for the theoretical computer science community. It covers a wide range of topics in the area of foundations of computer science. This time, 146 submissions from 30 countries were received, all in electronic form. Jochen Bern designed the electronic submission procedure, which performed marvelously. Many thanks to Jochen."

The Symposium on Theoretical Aspects of Computer Science (STACS) is held annually, alternating between France and Germany. The current volume cons- tutes the proceedings of the 16th STACS conference, organized jointly by the Special Interest Group for Theoretical Computer Science of the Gesellschaft fur ] Informatik (GI) in Germany, and Maison de l'Informatique et des Math e- tiques Discr etes (MIMD) in France. The conference took place in Trier { the oldest town in Germany, with more than 2 millennia of history. Previous symposia of the series were held in Paris (1984), Saarbru ]cken (1985), Orsay (1986), Passau (1987), Bordeaux (1988), Paderborn (1989), Rouen (1990), Hamburg (1991), Cachan (1992), Wur ] zburg (1993), Caen (1994), Mu ]nchen (1995), Grenoble (1996), Lu ]beck (1997), and Paris (1998). All proceedings of the series have been published in the Lecture Notes of Computer Science series of Springer-Verlag. STACShasbecome oneofthe mostimportantannualmeetingsin Europefor the theoretical computer science community. This time, altogether 300 authors from36countriesonv econtinentssubmittedtheirpapers.Eachsubmissionwas sent to v e members of the program committee for review. During the program committee session 51 out of the 146 submissions were accepted for presen- tion. In two of the selected papers the same result was proved independently."

This volume contains the papers selected for presentation at the 19th Colloquium on Trees in Algebra and Programming (CAAP '94), which was held jointly with the fifth European Symposium on Programming (ESOP '94) in Edinburgh in April 1994. Originally this colloquium series was devoted to the algebraic and combinatorial properties of trees, and their role in various fields of computer science. Taking into account the evolution of computer science, CAAP '94 focuses on logical, algebraic and combinatorial properties of discrete structures (strings, trees, graphs, etc.); the topics also include applications to computer science provided that algebraic or syntactic methods are involved. The volume contains 21 papers selected from 51 submissions as well as two invited papers.