RE: e and pi

[Drew Adams]

> The point is not whether `e' is being bound in a let or a defun.  

Correct.  The point is that one should easily be able to know which `e' is
involved at any point.  In particular (see the Subject), a global variable
(constant) intended to represent a math constant should have a global name that
proclaims that unambiguously: "I'm a global math constant".

> Rather, the point is that we should be able to use a variable like `e' as 
> a free variable in a closure.

No, that is a completely separate point - not the point of this thread.  Or at
least it should not be, even if lexical binding might be one way to circumvent
the `e' constant naming issue (without actually addressing and solving it
properly).

To see this, just substitute `x' or `frobfroth' for `e' in your last sentence
above.  Your point remains.  It is a valid point, but it is independent of the
question about the math constant `e'.

> We can do so only if it is governed by lexical binding.

Right.

So let's start another thread to sing hurrahs for the possibility of easier and
clearer lexical binding in Emacs.  It's just (logically) a different question
than that of poorly named constants `e' and `pi'.