That fixed it! I'll remember to use #lang racket stead of #lang scheme from now on. Thank you. <div class="gmail_quote">On Sat, Aug 14, 2010 at 11:36 AM, Noel Welsh <<a href="mailto:noelwelsh@gmail.com">noelwelsh@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">You're using #lang scheme instead of #lang racket, I expect. </blockquote></div>