Logic Colloquium '90
ASL Summer Meeting in Helsinki
Lecture Notes in Logic Series

Since their inception, the Perspectives in Logic and Lecture Notes in Logic series have published seminal works by leading logicians. Many of the original books in the series have been unavailable for years, but they are now in print once again. This volume, the second publication in the Lecture Notes in Logic series, is the proceedings of the Association for Symbolic Logic meeting held in Helsinki, Finland, in July 1990. It contains eighteen papers by leading researchers, covering all fields of mathematical logic from the philosophy of mathematics, through model theory, proof theory, recursion theory, and set theory, to the connections of logic to computer science. The articles published here are still widely cited and continue to provide ideas for ongoing research projects.

A note on the ordinal analysis of KPM Wilfried Buchholz; On the geometry of U-rank 2 types Steven Buechler and Ludomir Newelski; Definability and global degree theory S. Barry Cooper; About the irreflexivity hypothesis for free left distributive magmas Patrick Dehornoy; On ω1-complete filters Hans-Dieter Donder; Labelled deductive systems – a position paper D. M. Gabbay; Temporal expressive completeness in the presence of gaps D. M. Gabbay, I. M. Hodkinson and M. A. Reynolds; New foundations for mathematical theories Jaakko Hintikka; Absoluteness for projective sets Haim Judah; A division algorithm for the free left distributive algebra Richard Laver; Gentzen-type systems and resolution rule. Part II. Predicate logic Grigori Mints; An intuitionistic theory of lawlike, choice and lawless sequences Joan Rand Moschovakis; Sense and denotation as algorithm and value Yiannis N. Moschovakis; A transfinite version of Puiseux's theorem, with applications to real closed fields M. H. Mourgues and J.-P. Ressayre; On similarities of complete theories T. G. Mustafin; Decidability questions for theories of modules Françoise Point; On CH + 2aleph1 → (α)22 for α < ω2 Saharon Shelah; On the structure of gamma degrees Alan P. Silver.

Juha Oikkonen works in the Department of Mathematics at the University of Helsinki.
Jouko Väänänen works in the Department of Mathematics at the University of Helsinki.