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:
“My paramount object in this struggle is to save the Union, and is not either to save or to destroy slavery. If I could save the Union without freeing any slave, I would do it; and if I could save it by freeing all the slaves, I would do it; and if I could save it by freeing some and leaving others alone, I would also do that.”
—Abraham Lincoln (1809–1865)
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“In externals we advance with lightening express speed, in modes of thought and sympathy we lumber on in stage-coach fashion.”
—Frances E. Willard 1839–1898, U.S. president of the Women’s Christian Temperance Union 1879-1891, author, activist. The Woman’s Magazine, pp. 137-40 (January 1887)