GTQ: A Language and Tool for Game-Tree Analysis

Abstract

Abstract. The search engines of high-performance game-playing programs are becoming increasingly complex as more and more enhancements are added. To maintain and enhance such complex engines is a challenging task, and the risk of introducing bugs or other unwanted behavior during modifications is substantial. In this paper we introduce the Game Tree Query Language (GTQL), a query language specifically designed for analyzing game trees. The language can express queries about complex game-tree structures, including hierarchical relationships and aggregated attributes over subtree data. We also discuss the design and implementation of the Game Tree Query Tool (GTQT), a software tool that allows efficient execution of GTQL queries on game-tree log files. The tool helps program developers to gain added insight into the search process of their engines, as well as making regression testing easier. Furthermore, we use the tool to analyze and find interesting anomalies in search trees generated by a competitive chess program.

4. Relations between German merchants and islanders in the North Atlantic

“…293 On this basis Vilborg Ísleifsdóttir-Bickel suggests that the alleged support of Hamburg merchants for the rebellion of the northern bishop Jón Arason might have been related to their interests in the sulphur trade in that part of the island. 294 Due to many parish churches having extensive landholdings, the German merchants had many dealings with the parish priests. We find many priests among the customers of Clawes Monnickhusen and the Oldenburg merchants in Kumbaravogur.…”