How to Handle Partial Transformations II

摘要

This article is a follow-up to an earlier one in which I explored some of the basic ideas surrounding the study of partial transformations. The focus there was upon partial transformations on a single set. However, at the end of that prior article, I hinted at the possibility of studying partial transformations between two different sets through the introduction of an appropriate ternary operation. I expand here upon those earlier comments, and describe some of the contributions made in this area by the Russian geometer V.V. Wagner (1908-1981).