Decode this bug

[Daniel Wang]

"Stephen Weeks" <sweeks@intertrust.com> writes:

> Yes.  Every label, variable, etc. must be defined in exactly one
> place.  This is so that the property lists can be used.
> 

Okay.. I'm not explicitly maintaining this invariant.. but I don't think my
original code has any duplicate vars.. (I'll cons up a pass to make sure..)

> > inferHandlers ==> 
> > ==> 
> > Bug: fold2
> > 
> > uncaught exception Bug
> 
> This is the handler inference pass.  The type system must be able to
> assign a unique local handler stack to each local jump.

Hmm. I'm not introducting any local jumps, just sticking to the DirectExp
interface and assuming it does the "right thing". Maybe it's a reuse of a
variable some place... 

Thanks a I've got a few questions about the semantics of the types it all
looks sensible but there are a few details I need to straighten out. I'll
batch up the questions after I finish fixing the alpha renaming problem.