The theory of factorization in commutative rings, including Euclidean domains, principal ideal domains, unique factorization domains. Criteria for existence and uniqueness of factorization in various integral domains.
Below, you should see a graph of the definitions and statements, and the deductive reliances among them. This graph may be too small to read as displayed below. Until a zoomable svg applet is installed, you can try one of the following (in Firefox):
Right-click on the graph, and click on "This Frame", then "Show only this frame".
Right-click on the graph, and click on "This Frame", then "View frame source".
The "frame source" is the SVG (scalable vector graphics) file, which can then be saved, and viewed and edited using many software utilities, such as Inkscape.