Date of Original Version
Annals of Pure and Applied Logic 139 (1-3), May 2006:138-184.
Abstract or Table of Contents
We develop fundamental aspects of the theory of metric, Hilbert, and Banach spaces in the context of subsystems of second-order arithmetic. In particular, we explore issues having to do with distances, closed subsets and subspaces, closures, bases, norms, and projections. We pay close attention to variations that arise when formalizing definitions and theorems, and study the relationships between them.