>Actually, I'm not sure -- it's conceivable that the ending point would ALSO >move inward for a different starting point within the original match. But >the ending point should NEVER be advanced further -- that's where the >"leftmost over nongreedy" rule should apply instead... Please show us your implementation for a pattern matching engine that lets the current end-point vary. This is very exciting, because now you can relax the restriction that lookbehinds must be constant width. --tom