| Personally I thought Stardog was trash, but if I'd had different requirements I might be happy with it. The trouble w/ OWL as I see it (talked about in that TR) is that people don't really want "first order logic", but they want "first order logic + arithmetic" which is a nightmare that Kurt Godel warned you about. (That ISO 20022 which that TR is related to is about the financial domain which is all about arithmetic) After Doug Lenat's death a lot of stuff came out that revealed the problems w/ Cyc, not least that even if you try to build something that is "knowledge based" it can't practically solve all the problems you want using a SMT-based strategy but you have to build a library of special purpose algorithms for everything you want to do and it turns out to be a godawful mess. I'm disappointed that the semweb community hasn't made a serious crack at usable and efficient production rules (dealing w/ problems like negation, controlling execution order, RETE execution, retraction) instead we get half-answers like SPIN with fixed-point execution (used an even more half-baked version of that to research that TR, gets you somewhere). Of course, production rules never got standardized in any domain because nobody can agree on the way to address those four issues even though it usually isn't hard to find an answer that's fine for a particular application. (It's a frequently problem that experts on a technology can get by on half-baked specific answers that would need a general solution if they were going to be useful for a general audience. One reason why parser generators are so bad is that if you understand parser generators enough to write a parser generator you aren't bothered by the terrible developer experience of parser generators.) |