Some special elements and pseudo inverse functions in groupoids

Abstract

In this paper, we consider a theory of elements u of a groupoid (X,∗) that are associated with certain functions uˆ:X→X , pseudo-inverse functions, which are generalizations of the inverses associated with units of groupoids with identity elements. If classifying the elements u as special of one of twelve types, then it is possible to do a rather detailed analysis of certain cases, leftoids, rightoids and linear groupoids included, which demonstrates that it is possible to develop a successful theory and that a good deal of information has already been obtained with much more possible in the future.