> Oh he did not ask for permutations, he asked for combinations, are we > being unfriendly? No, not at all. I was simply making the observation that selecting the correct (often English due to the availability of material in that language) word can open a goldmine of results in Google searches. Sometimes all one can do is explain a concept, because one doesn't have the vocabulary to reduce it to a single, searchable word. At least, that's been my experience with the non-native languages I speak poorly, and I'm counting mathematics as one of those languages here! Chris -- Posted via http://www.ruby-forum.com/.