Thank you. I'll take a look. In retrospect I think there might be several ways to improve performance by using other data structures to index the facts, but I

Thank you. I'll take a look. In retrospect I think there might be several ways to improve performance by using other data structures to index the facts, but I haven't had the time to work on it lately. There is a pull request from someone that I'm still looking at, which might just spur me on to think about it some more.