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:
“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)
“We are constantly thinking of the great war ... which saved the Union ... but it was a war that did a great deal more than that. It created in this country what had never existed before—a national consciousness. It was not the salvation of the Union, it was the rebirth of the Union.”
—Woodrow Wilson (1856–1924)
“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)