Researcher Summary
Research interests include: constructive foundations of mathematics: in particular, constructive foundations of analysis (real and functional) and topology (the axiomatic theory of apartness), and ring theory; constructive reverse mathematics: classifying constructive proofs by the principles they require, and nonconstructive proofs by the nonconstructive principles they depend on; computability and abstract complexity theory; mathematical economics: the numerical representation of preference relations; demand functions; equilibrium theory; and quantum logic and operator-theoretic foundations of physics.