Why not make this explicit by deprecating define/contract and support this use case with a submodule. They lightweight enough and makes boundary demarcations consistent, explicit and simple. Module -> boundary. <div class="gmail_quote">On Nov 30, 2012 12:05 PM, "Matthias Felleisen" <<a href="mailto:matthias@ccs.neu.edu">matthias@ccs.neu.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On Nov 30, 2012, at 10:15 AM, Greg Hendershott wrote: >> This is a complete misunderstanding. > > Sometimes I feel like a kid in the room while the adults are talking. > When it comes to contracts, I have to stipulate that most of you are > smarter than me and have thought about this longer than me. Apologies. My opening wasn't meant to say "I am smarter" but I wanted to send a strong message about define/contract. It really introduces a boundary and in some strange sense your (possibly misleading) microbenchmark exposes this constraint too. ____________________ Racket Users list: <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a> </blockquote></div>