A categorical treatment of pre- and post- conditions.- Colourings of planar maps and the equality of two languages.- On the equivalence of synchronization sets.- Inner and mutual compatibility of basic operations on module specifications.- Exact computation sequences.- An algebraic theory of flowchart schemes.- An algebraic formalism for graphs.- Membership for growing context sensitive grammars is polynomial.- Weighted graphs : A tool for logic programming.- Classical and incremental evaluators for attribute grammars.- Transformation strategies for deriving on line programs.- Probabilistic Ianov's schemes.- Alternating bottom-up tree recognizers.- Bottom-up recursion in trees.- Basic tree transducers.- Trie partitioning process: Limiting distributions.- Random walks, gaussian processes and list structures.- Random walks on trees.- Infinite trees, markings and well foundedness.- Computable directory queries.- Relating type-structures partial variations on a theme of Friedman and Statman.- On applications of algorithmic logic.