Union
The union used in set theory is defined in terms of a logical disjunction: x ∈ A ∪ B if and only if (x ∈ A) ∨ (x ∈ B). Because of this, logical disjunction satisfies many of the same identities as set-theoretic union, such as associativity, commutativity, distributivity, and de Morgan's laws.
Read more about this topic: Logical Disjunction
Famous quotes containing the word union:
“... as women become free, economic, social factors, so becomes possible the full social combination of individuals in collective industry. With such freedom, such independence, such wider union, becomes possible also a union between man and woman such as the world has long dreamed of in vain.”
—Charlotte Perkins Gilman (1860–1935)
“The rage for road building is beneficent for America, where vast distance is so main a consideration in our domestic politics and trade, inasmuch as the great political promise of the invention is to hold the Union staunch, whose days already seem numbered by the mere inconvenience of transporting representatives, judges and officers across such tedious distances of land and water.”
—Ralph Waldo Emerson (1803–1882)
“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)