Logical Disjunction - Union

Union

The union used in set theory is defined in terms of a logical disjunction: xAB if and only if (xA) ∨ (xB). 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.

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Famous quotes containing the word union:

    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)

    Maybe we were the blind mechanics of disaster, but you don’t pin the guilt on the scientists that easily. You might as well pin it on M motherhood.... Every man who ever worked on this thing told you what would happen. The scientists signed petition after petition, but nobody listened. There was a choice. It was build the bombs and use them, or risk that the United States and the Soviet Union and the rest of us would find some way to go on living.
    John Paxton (1911–1985)

    How can I explain the difference to me between America and Russia?... the America I’ve known is a place where men on horseback escort union marchers, the Russia I’ve known is a place where men on horseback slaughter young Socialists and Jews.
    Golda Meir (1898–1978)