http://www-ps.informatik.uni-kiel.de/~sebf Department of Computing Science, Christian-Albrechts-University of Kiel, Germany Mon, 17 Nov 2008 20:02:09 +0000 http://backend.userland.com/rss092 en In order to experiment with [constraint monads][cmc] I have implemented a simple SAT solver based on the [Davis-Putnam-Logemann-Loveland (DPLL) algorithm][dpll]. The [marked-up code][lhs] is meant for human consumption -- if you want to execute it, you should fetch the latest version from my [git repository][git]. [cmc]: /~sebf/projects/constraint-monad.html "Constrained Monadic Computations" [dpll]: http://en.wikipedia.org/wiki/DPLL_algorithm ... http://www-ps.informatik.uni-kiel.de/~sebf/projects/sat-solver.html In a [previous post][cmc] I have explained how to extend arbitrary instances of `MonadPlus` with constraint solving capabilities. Now, I'll focus on how to use this functionality to implement lazy non-deterministic computations on top of a `MonadPlus`. [cmc]: /~sebf/projects/constraint-monad.html "Constrained Monadic Computations" http://www-ps.informatik.uni-kiel.de/~sebf/projects/lazynd.html Recently, I thought about two seemingly different topics which turn out to form a fruitful combination. One thing I have been thinking about a lot is how to model functional-logic programming in Haskell without using impure features to ensure call-time choice semantics of lazy computations. The other thing is how to ... http://www-ps.informatik.uni-kiel.de/~sebf/projects/constraint-monad.html Die Vorlesung _Informatik für Nebenfächler_ findet Montags und Dienstags von 16-18 Uhr im CAP3(III) statt. Am _Dienstag dem 21. Oktober_ ist die erste Vorlesung, in der auch die Anmeldung in der Studierenden-Datenbank erfolgt. Falls Sie nicht an der Anmeldung teilgenommen haben, können Sie sich auch [online in der StudiDB anmelden][sdb]. ... http://www-ps.informatik.uni-kiel.de/~sebf/ws0809/ifn.html Unhappy with the conclusion of this article, I began to develop a framework for lazy functional-logic programming in Haskell that allows to compare different search strategies in an in other respects identical environment. Specifically, I aim at comparing complete strategies like breath-first search or FBackTrack (cf. aforementioned articel) w.r.t. their ... http://www-ps.informatik.uni-kiel.de/~sebf/projects/haskell-flp.html After my talk at FLOPS 2008, Chung-chieh Shan 單中杰 pointed out that — because test-case generation is a search problem — heuristic search techniques from AI could be applied to improve the usual-case performance of test-case generation. Specifically, he pointed me at Adaptive Tree Search (ATS) which aims at finding ... http://www-ps.informatik.uni-kiel.de/~sebf/projects/adaptive-search.html At FLOPS 2008 Oleg Kiselyov showed me FBackTrack — a simple instantiation of the MonadPlus class in Haskell which is fair (like breadth-first search) and seems to consume considerably less memory than BFS. I immediately started following an obvious plan: implement a traversal on Curry's SearchTree datatype treating choices like ... http://www-ps.informatik.uni-kiel.de/~sebf/projects/fair-search.html with Herbert Kuchen ICFP '08: Proceedings of the 13th ACM SIGPLAN International Conference on Functional Programming © ACM Press pdf slides bib http://www-ps.informatik.uni-kiel.de/~sebf/pub/icfp08.html with Josep Silva, Salvador Tamarit and German Vidal LOPSTR '07: Logic-Based Program Synthesis and Transformation © Springer pdf bib http://www-ps.informatik.uni-kiel.de/~sebf/pub/lopstr07.html Das Praktikum findet Dienstags und Donnerstags von 16 bis 18 Uhr (st) im Raum 715 des Uni Hochhauses statt. Die Veranstaltung im Univis: Fortgeschrittenenpraktikum Bachelor Projektmodul Aktuelle Informationen zu dieser Veranstaltung gibt es auf der Projektwebsite. http://www-ps.informatik.uni-kiel.de/~sebf/sose08/webprog.html