Subset Diagram. Useful for csec maths practice. It is related to the maze running problem wherein the possible routes to an exit are sought.
There is a special notation for this empty set by the way. Another way to define a subset is. Set notation is used in mathematics to essentially list numbers objects or outcomes.
Useful for csec maths practice.
A subset shows up as a circle within a circle in a venn diagram. To answer your two questions directly. Useful for csec maths practice. A subset shows up as a circle within a circle in a venn diagram.