Binding functions vs packages.

[Richard M. Stallman <RMS at MIT-AI>]

The use of syntactically nested functions is very bad for
extensibility.  If I have FOO which calls BAR, and BAR is defined
separately, I can redefine either one separately.
If FOO contains a LABELS which defines BAR, then I cannot redefine
just one of them without redefining the other (trivially).

I hear that GJS and HAL have a plan for manipulating "lexical"
environments in a fashion which is not really syntactically nested,
and this may solve the problem.  But it is not simply ordinary lexical
binding of function names.  Anything which is really syntactically
local does not do the job.