The road to two theorems of logic

William L. Craig

pp. 333-339

in: Essays in honor of William Craig, Synthese 164 (3), 2008.

Abstract

Work on how to axiomatize the subtheories of a first-order theory in which only a proper subset of their extra-logical vocabulary is being used led to a theorem on recursive axiomatizability and to an interpolation theorem for first-order logic. There were some fortuitous events and several logicians played a helpful role.