A graph search algorithm. A* is guaranteed to find a minimal soLUtion path before any other soLUtion paths, if a soLUtion exists, in other words, it is an "admissible" search algorithm. Each path is assigned a vaLUe based on the cost of the path (e.g. its length) and an (under)estimate of the cost of completing the path, i.e. the cost of a path from the end of the current path to a soLUtion. (1995-03-31)