Symbol
The mathematical symbol for logical disjunction varies in the literature. In addition to the word "or", and the formula "Apq", the symbol "", deriving from the Latin word vel for "or", is commonly used for disjunction. For example: "A B " is read as "A or B ". Such a disjunction is false if both A and B are false. In all other cases it is true.
All of the following are disjunctions:
The corresponding operation in set theory is the set-theoretic union.
Read more about this topic: Logical Disjunction
Famous quotes containing the word symbol:
“Your true traveller finds boredom rather agreeable than painful. It is the symbol of his liberty—his excessive freedom. He accepts his boredom, when it comes, not merely philosophically, but almost with pleasure.”
—Aldous Huxley (1894–1963)
“The symbol of perpetual youth, the grass-blade, like a long green ribbon, streams from the sod into the summer, checked indeed by the frost, but anon pushing on again, lifting its spear of last year’s hay with the fresh life below. It grows as steadily as the rill oozes out of the ground.... So our human life but dies down to its root, and still puts forth its green blade to eternity.”
—Henry David Thoreau (1817–1862)
“A symbol is indeed the only possible expression of some invisible essence, a transparent lamp about a spiritual flame; while allegory is one of many possible representations of an embodied thing, or familiar principle, and belongs to fancy and not to imagination: the one is a revelation, the other an amusement.”
—William Butler Yeats (1865–1939)