High Quality Content by WIKIPEDIA articles! Allen's Interval Algebra is a calculus for temporal reasoning that was introduced by James F. Allen in 1983. The calculus defines possible relations between time intervals and provides a composition table that can be used as a basis for reasoning about temporal descriptions of events. For reasoning about the relations between temporal intervals, Allen's Interval Algebra provides a composition table. Given the relation between X and Y and the relation between Y and Z, the composition table allows for concluding about the relation between X and Z. Together with a converse operation, this turns Allen's Interval Algebra into a relation algebra.