Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.In mathematics and set theory, a total order, linear order, simple order, or (non-strict) ordering is a binary relation (here denoted by infix ) on some set X. The relation is transitive, antisymmetric, and total. A set paired with a total order is called a totally ordered set, a linearly ordered set, a simply ordered set, or a chain. Contrast with a partial order, which lacks the third condition. A relation having the property of "totality" means that any pair of elements in the set of the relation are mutually comparable under the relation.