Lectures on intuitionism.- Realizability: A retrospective survey.- Some applications of Kleene's methods for intuitionistic systems.- Notes on intuitionistic second order arithmetic.- Some properties of intuitionistic zermelo-frankel set theory.- Ouelques Resultats sur les Interpretations Fonctionnelles.- Combinator realizability of constructive finite type analysis.- The arithmetic theory of constructions.- The priority method for the construction of recursively enumerable sets.- Admissible ordinals and priority arguments.- Abstract computability versus analog-generability (a survey).- Infinitary combinatorics.- The maximum sum of a family of ordinals.- Effective implications between the "finite" choice axioms.- On descendingly complete ultrafilters.- XVI. A model for the negation of the axiom of choice.- Filters closed under MAHLO's and GAIFMAN's operation.- On chromatic number of graphs and set systems.- Countable models of set theories.- Errata.- Descriptive set theory in .- Modal model theory.- A preservation theorem for interpretations.- Vaught sentences and Lindstr¿m's regular relations.