All, Here is a deliberately provocative posting (with running code -- that works in OCaml as well as Haskell -- and a shameless plug for BNFC) on the process of introducing naming and name management into the design of data structures. Comments greatly appreciated. Best wishes, --greg -- L.G. Meredith Managing Partner Biosimilarity LLC 806 55th St NE Seattle, WA 98105 +1 206.650.3740 http://biosimilarity.blogspot.com