An effective two-level proof-number search algorithm

An effective two-level proof-number search algorithm

The paper presents a new proof-number (PN) search algorithm, called PDS-PN. It is a two-level search (like PN), which performs at the first level a depth-first Proof-number and Disproof-number Search (PDS), and at the second level a bestfirst PN search. Hence, PDS-PN selectively exploits the power of both PN and PDS. Experiments in the domain of Lines of Action are performed. They show that wit...

Generalized Proof Number Search

We present Generalized Proof Number Search (GPNS), a Proof Number based algorithm able to prove positions in games with multiple outcomes. GPNS is a direct generalization of Proof Number Search (PNS) in the sense that both behave exactly the same way in games with two outcomes. However, GPNS targets a wider class of games. When a game features more than two outcomes, PNS can be used multiple ti...

PDS-PN: A New Proof-Number Search Algorithm

The paper introduces a new proof-number (PN) search algorithm, called PDS-PN. It is a two-level search, which performs at the first level a depth-first Proof-number and Disproof-number Search (PDS), and at the second level a best-first PN search. First, we thoroughly investigate four established algorithms in the domain of LOA endgame positions: PN, PN, PDS and αβ search. It turns out that PN a...

Randomized Parallel Proof-Number Search

Proof-Number Search (PNS) is a powerful method for solving games and game positions. Over the years, the research on PNS has steadily produced new insights and techniques. With multi-core processors becoming established in the recent past, the question of parallelizing PNS has gained new urgency. This article presents a new technique called Randomized Parallel Proof-Number Search (RP–PNS) for p...

Proof-Number Search and Transpositions