A constructive valuation interpretation for classical logic and its use in witness extraction -- Varieties of increasing trees -- Origin functions in ?-calculus and term rewriting systems -- An algebraic approach to the interpretation of recursive types -- Decidability of reachability and disjoint union of term rewriting systems -- A complete type inference algorithm for simple intersection types -- Monadic second-order definable graph transductions -- CTL* and ECTL* as fragments of the modal ?-calculus -- Power domains supporting recursion and failure -- Parallel contraction of fibonacci trees and prefix computations on a family of interconnection topologies -- Must preorder in non-deterministic untyped ?-calculus -- A programming language for deriving hypergraphs -- Graph grammars as context-dependent rewriting systems: A partial ordering semantics -- Empty stack Pushdown ?-tree automata -- Modulo counting quantifiers over finite trees -- Finite tree automata with cost functions -- Partial type assignment in left linear applicative term rewriting systems -- A linear algorithm for solving fixed-point equations on transition systems -- Beyond conditional equations.

This volume contains selected papers presented at the seventeenth Colloquiumon Trees in Algebra and Programming (CAAP) held jointly with the European Symposium on Programming (ESOP) in Rennes, France, February 26-28, 1992 (the proceedings of ESOP appear in LNCS 582). The previous colloquia were held in France, Italy, Germany, Spain, Denmark and England. Every even year, as in 1992, CAAP is held jointly with ESOP; every other year, it is part of TAPSOFT (Theory And Practice of SOFTware development). In the beginning, CAAP was devoted to algebraic and combinatorial properties of trees and their role in various fields of computer science. The scope of CAAP has now been extended to other discrete structures, like graphs, equations and transformations of graphs, and their links with logical theories. The programme committee received 40 submissions, from which 19 papers have been selected for inclusion inthis volume.