Union and Intersection
If A and B are disjoint sets, then
From this, one can show that in general the cardinalities of unions and intersections are related by
Read more about this topic: Cardinality
Famous quotes containing the words union and, union and/or intersection:
“Visitors who come from the Soviet Union and tell you how marvellous it is to be able to look at public buildings without advertisements stuck all over them are just telling you that they can’t decipher the cyrillic alphabet.”
—Clive James (b. 1939)
“These semi-traitors [Union generals who were not hostile to slavery] must be watched.—Let us be careful who become army leaders in the reorganized army at the end of this Rebellion. The man who thinks that the perpetuity of slavery is essential to the existence of the Union, is unfit to be trusted. The deadliest enemy the Union has is slavery—in fact, its only enemy.”
—Rutherford Birchard Hayes (1822–1893)
“You can always tell a Midwestern couple in Europe because they will be standing in the middle of a busy intersection looking at a wind-blown map and arguing over which way is west. European cities, with their wandering streets and undisciplined alleys, drive Midwesterners practically insane.”
—Bill Bryson (b. 1951)