(Or "linear assignment") Any problem involving minimising the sum of C(a, b) over a set P of pairs (a, b) where a is an element of some set A and b is an element of set B, and C is some function, under constraints such as "each element of A must appear exactly once in P" or similarly for B, or both. For example, the a' s could be workers and the b' s projects. The problem is "linear" because the "cost function" C() depends only on the particular pairing (a, b) and is independent of all other pairings. . . . . [Algorithms?] (1999-07-12)