There are a couple things that should be noted about the document. First, it was constructed from purely conceptual discussions we had on the Loci mailing list, before we merged to form Piper. Second, I think the major difference between the way we conceptualized command compilation working for Loci, and the way it works for Overflow, is that the Loci document refers to "string-adding terminals", while Overflow uses "string-adding nodes". I believe that they are functionally equivalent, and I need to modify the document to show how it is done (or could be improved) in Overflow. Anyway, it never ceases to amaze me how we all developed very similar concepts independently. Cheers. Jeff -- J.W. Bizzaro jeff at bioinformatics.org Director, Bioinformatics.org: The Open Lab http://bioinformatics.org/~jeff "All those scientists--they're all alike! They say they're working for us, but what they really want is to rule the world!" -- Angry Villager, Young Frankenstein --