A temp var is declared in the scope where it is first assigned.

*EEEK*  I've used a couple of programming languages with that rule,
and it is an extremely good way to introduce bugs.  We already _have_
Smalltalk syntax for declaring precisely where you want temp vars to
be; what's wrong with that?  (Mind you, I had some trouble _believing_
the Smalltalk syntax, e.g. [:foo||bar| especially as || is a token in
ANSI Smalltalk, but I did manage to get a parser to parse it correctly.
Still, _any_ explicit syntax for this is better than making it implicit
that way.  Generations of Squik programmers will curse this decision if
there ever are any such generations.