A binary search searches *sorted* lists using a divide and conquer
technique. On each iteration the search domain is cut in half, until the
result is found. The computational complexity of a binary search is O(log
n).

The binary search algorithm implemented in this module is known as a
_Deferred Detection_ variant on the traditional Binary Search. Deferred
Detection provides *stable searches*. Stable binary search algorithms have
the following characteristics, contrasted with their unstable binary search
cousins:

* * In the case of non-unique keys, a stable binary search will always
return the lowest-indexed matching element. An unstable binary search
would
return the first one found, which may not be the chronological first.