Inverse Semigroups and Locally Compact Groupoids

Abstract

In this section we give a brief and largely self-contained account of the results on inverse semigroups that will be required in the sequel. The results we need from the algebraic theory of semigroups are well-known, and are contained in the standard textbooks (such as [50, 51, 133, 202]). However, for the convenience of the reader and for the purpose of establishing notation, an account concentrating on what we will need later from that theory is desirable.