Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

The subject of this book is string-rewriting systems. It is generally accepted that string-rewriting was first introduced by Axel Thue in the early part of this century. In the 1960's and early 1970's, it received renewed attention due to interest in formal language theory. In the 1980's and 1990's, it has received more interest since it can be viewed as a special case of term rewriting, a subject that has become important in the study of automated deduction. Today, string-rewriting is studied by researchers in theoretical computer science and also by researchers interested in the foundations of artificial intelligence. A sketch of the way that the subject has developed is contained in Chapter 0, and the reader is advised to begin with that chapter. Both authors have been active in the field and have lectured on the subject in several universities. Lecture notes have been produced and dis tributed. This monograph is a result of revising and rewriting those notes. It represents an attempt by the authors to present the concepts that the authors consider to be most fundamental and to gather together the most useful results in such a way that they can be understood and used in studies relating to more general rewriting, to automated deduction, and to algo rithmic problems of algebraic structures. This monograph is written for independent study by researchers in the oretical computer science or in the foundations of artificial intelligence."

These proceedings contain most of the papers that werepresented at the Second International Conference on Language and Automata Theory and Applications (LATA 2008), held in Tarragona, Spain, during March 13-19, 2008. The scope of LATA is rather broad, including: words, languages and - tomata; grammars (Chomsky hierarchy, contextual, multidimensional, uni?- tion, categorial, etc. );grammarsandautomataarchitectures;extendedautomata; combinatorics on words; language varieties and semigroups; algebraic language theory; computability; computational, descriptional, and parameterized c- plexity;decidability questions onwordsandlanguages;patterns andcodes;s- bolic dynamics; regulated rewriting; trees, tree languages and tree machines; term rewriting; graphs and graph transformation; power series; fuzzy and rough languages; cellular automata; DNA and other models of bio-inspired comp- ing; quantum, chemical and optical computing; biomolecular nanotechnology; automata and logic; algorithms on automata and words; automata for s- tem analysis and program veri?cation; automata, concurrency and Petri nets; parsing; weighted machines; transducers; foundations of ?nite state technology; grammatical inference and algorithmic learning; text retrieval, pattern mat- ing and pattern recognition; text algorithms; string and combinatorial issues in computationalbiologyandbioinformatics;mathematicalevolutionarygenomics; language-based cryptography; data and image compression; circuits and n- works; language-theoretic foundations of arti?cial intelligence and arti?cial life; digital libraries; and document engineering. LATA 2008 received 134 submissions. Each of them was reviewed by at least three Program Committee members plus, in most cases, by additional external referees. After a thorough and vivid evaluation phase the committee decided to accept 40 papers (which means an acceptance rate of 29. 85%