The Computers: Algorithms: (Sorting and Searching Algorithms )

Techniques and approaches for data ordering, arrangement and lookup. Sorting and Searching Algorithms Computers.

For sorting, either a weak order, "should not come after", can be specified, or a strict weak order, "should come before" (specifying one defines also the other, the two are the complement of the inverse of each other, see operations on binary relations ). (wikipedia)