It not only introduces the topics, but shows how they form examples of abstract mathematical structures such as groups, rings and fields, and how algebra can be developed on an axiomatic foundation.

In a relational database, a collection of rules for dealing with tables; for example, JOIN, UNION and INTERSECT. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

In algebra, letters are used when numbers are not known. Algebraic terms, such as \(2s\) or \(8y\), leave the multiplication signs out. So rather than \(2 \times s\), write \(2s\), and rather than ...