See the SPCF paper. There evaluation contexts may bind. -- Matthias On Mar 12, 2007, at 10:41 AM, Dave Herman wrote: > Matthias Felleisen wrote: >> You don't need the freshness condition for this language. -- Matthias > > What kinds of constructs would you need that side condition for? I > imagine your set!-as-letrec trick might require it. > > Dave