Abstract
As each chapter has a full introduction, a few general remarks about the thesis will suffice here.The reader is assumed to be familiar with the elements of order theory M. semigroup and groupoid theory^], and topology [l9j. The thesis is almost fully selfcontained apart from this. The basic notation and terminology is that of [A], [9] and [19]; there are some minor changes in terminology between chapters, but no confusion should arise.
For ease of reference, items  whether they are theorems, lemmas, or whatever  are numbered consecutively within a given section of a given chapter, with the reference numbers showing first. Thus '4.2.10 Theorem1, referred back to as Theorem 4.2.10, is the tenth item in the second section of Chapter 4, where the item here is a theorem. The item which precedes Theorem 4.2.10, is a lemma, marked '4.2.9 Lemma', and referred back to as Lemma 4.2.9. Further, ^ 1.2 , say, refers to the second section of Chapter 1.
Date of Award  1970 

Original language  English 
Awarding Institution 
