A framework for game tree algorithms

A unifying framework for game tree algorithms is GSEARCH, designed by Ibaraki. In general, a relatively great deal of memory is necessary for instances of this framework. Another framework from Ibaraki is RSEARCH, in which the use of memory can be controlled. In this paper variants of above frameworks are introduced, to be called Gsearch and Rsearch respectively. It is shown that, in these frameworks, the classical alpha-beta algorithm is the depth-first search instance and H* is a best first search instance. Furthermore two new algorithms, Maxsearch and Minsearch, are presented, both as best-first search instances. Maxsearch is close to SSS* and SSS-2, whereas Minsearch is close to dual SSS*.