Either of a pair of symbols, , used for various purposes, e.g. to enclose text inserted or replaced by an editor, to indicate various mathematical operations, and to indicate a link in MediaWiki syntax
We must, in short, employ a special bracket for operative relations ; and the square bracket is the most convenient. Hence x denotes that a + bβ operates on x, and n denotes that φ operates on itself n - 1 times.
One of a pair of marks, , used to enclose written or printed material or to indicate a mathematical expression considered in some sense a single quantity. one of the pair of signs that are used for enclosing information American Equivalent: bracketin square brackets