Documentation strings and function.

["Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>]

Well, there are things that are hard to express in the simple syntactic
notation Guy chose to use: exactly three of these things are allowed if
and only if one of those things is present, etc.  I think that there are
several places in the book where the syntactic expressions provide some
necessary conditions, but where further restrictions on the format are
specified by the text.

In order to fix all of these things, so that the syntactic expressions
provide a necessary and sufficient formal grammar for the language, we
would have to go to a much more complex notation, which would be
much tougher on the average reader.  I think that the current system,
where there are syntactic expressions that are sometimes further
restricted by English statements, is the way to go.

I agree that the statement forbidding multiple doc-strings should not be
as well-hidden as it currently is.  The fact that people have missed it
is pretty good evidence that it is not visible enough.

-- Scott