... shade SCHAUM& apos ;S OUTLINE OF THEORY AM)PROBLEMS OF PROBABILITY SEYMOURLIPSCHUTZ, Ph.D. Professor of MathematicsTemple University SCHAUM& apos ;S OUTLINE SERIES McGRAW-HILL New York SanFrancisco Washington, ... is also closed under finite(countable) intersections.6 SET THEORY [CHAP. 1 Solved ProblemsSETS, ELEMENTS, SUBSETS 1.1. Let A = {x:3x= 6}. Does A = 21 A is the set which consists of the single ... helpclarify these situations, we usually use the wordclass or family for such a set. The words subclassand subfamily have meanings analogous to subset.Example 1.14: The members of the class {{2,3},{2},...