[Tutor] lambda in a loop

[Danny Yoo]

> Just to be able to talk about things, let's give a name to the global
> namespace as: "G".
>
> Whenever we call a function, we build a new environment that's chained up
> to the one we're in at the time of function construction.  This
> corresponds to what people's ideas of the "stack frame" is.

Argh.  Scratch that last sentence in there; I thought I deleted that part.
The environment model has nothing to do with the stack traceback; my
apologies!