Foundations of Mathematics Vol . 2 ( 1939 )

The aim of this book is to provide an exhaustive [eingehende] orientation over the current material [gegenwärtigen Stoff ] of Hilbert’s proof theory. Despite the fact that very little has been achieved here so far compared to the goals of the theory, there still are plenty of succinct [prägnant] results, viewpoints, and proof ideas that seem worthwhile to make aware of. The purpose of the book led to two main themes for the design of the content of this second volume.—On the one hand, to present in detail the principal proof-theoretic approaches of Hilbert that follow from the -symbol together with their implementations. A substantial part of the investigations presented here has not been published yet at all, except for some bare hints. Thus, not only there is interest