# ordered pair

An ordered pair is a pair of mathematical objects for which the order of those objects is significant.

For objects and , the ordered pair with as the first element and as the second is denoted: .

Since the order is important, = if and only if and . This also means that the ordered pair is only equal to its reverse, , when .

This enforced order is one way in which ordered pairs are different from sets, whose order does not matter. ie., .

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