Roster method is notation that describes a set by stating a property an element must have to be a member. 12. Cantor diagonalization argument is a proof technique used to show that a set of numbers is countable. 13. If A and B are two zero-one matrices, then the notation A∨B is called the meet of A and B. 14. A set that either is finite or can be placed in one-to-one correspondance with the set of positive integers is called a countable set. 15. The codomain of a function f is also called range. 16. The inverse of a function f is the function that reverses the correspondence given by f (where f is a bijection).