[plt-dev] `unsafe-fl' and unboxing

> No! 'identifier?' does not check whether a syntax object represents  
> a variable reference, given 1) identifier macros and 2) #%top  
> transformers for unbound variables. If you really, really want to  
> check if something is a variable reference, 'local-expand' it and  
> look at the result.

Oh, yes, of course. All the more reason to hope mzscheme supports  
MWBoR. (Eli's email suggests it does.)

Dave