Pair

Pair may refer to:

Medicine

Pair (parliamentary convention)

In parliamentary practice, pairing is an informal arrangement between the government and opposition parties whereby a member of a House of Parliament agrees or is designated by the party whip to abstain from voting while a member of the other party needs to be absent from the House due to other commitments, illness, travel problems, etc. A pairing would usually be arranged or approved by the party whips and will usually not apply for critical votes, such as no-confidence votes.

The member abstaining from voting is referred to as a pair. In the United States, pairing is an informal arrangement between members and the pairs are called live pairs.

An alternative method of maintaining the relative voting positions of parties in a legislative body is proxy voting, which is used, for example, in New Zealand.

Examples

Australia

In Australia, following the 2010 federal election, the Gillard Government formed a minority government with the support of a number of votes from minor parties and independents, and the Opposition refused to grant automatic pairing, leading to some embarrassment and reversals for the opposition when, for example, a pair was initially not given for a member to care for her sick baby or to attend at the birth of his baby.

Ordered pair

In mathematics, an ordered pair (a, b) is a pair of mathematical objects. The order in which the objects appear in the pair is significant: the ordered pair (a, b) is different from the ordered pair (b, a) unless a = b. (In contrast, the unordered pair {a, b} equals the unordered pair {b, a}.)

Ordered pairs are also called 2-tuples, or sequences of length 2; ordered pairs of scalars are also called 2-dimensional vectors. The entries of an ordered pair can be other ordered pairs, enabling the recursive definition of ordered n-tuples (ordered lists of n objects). For example, the ordered triple (a,b,c) can be defined as (a, (b,c)), i.e., as one pair nested in another.

In the ordered pair (a, b), the object a is called the first entry, and the object b the second entry of the pair. Alternatively, the objects are called the first and second coordinates, or the left and right projections of the ordered pair.

Cartesian products and binary relations (and hence functions) are defined in terms of ordered pairs.