Partially Ordered Sets
In this section, our attention is directed toward some of the deeper concepts of set theory. The topics to be considered will be treated in a fairly elementary, non-rigorous manner, yet some essential ideas will be developed and some major results will be established. The ideas to be considered are the fundamental tools for work in a very broad spectrum of mathematics. Without these tools, much of mathematics today simply could not exist in its present form. Much of the later material in this chapter is 20th century mathematics and as a result of its comparative newness, this body of information is growing and changing as new results are established. Interested readers are encouraged to consult the reading list to gain a wider perspective and learn some of the exciting history associated with these topics.