Match the following. 1. a set within a set; all the elements of one set are also contained in another set function 2. the set of all second elements of a relation R x R 3. any relation in which no two ordered pairs have the same first element domain 4. all the possible combinations of real numbers denoting ordered pairs range 5. the set of all first numbers of each ordered pair subset 6. a group or collection of objects element 7. any set of ordered-pair numbers relation 8. an object in a set ordered pair 9. a pair of numbers that are grouped together set