for review: add nested modules [5/5]

[Mark Anthony BROWN]

> 
> On 04-Mar-1998, Peter Schachte <pets at students.cs.mu.OZ.AU> wrote:
> > On Thu, 26 Feb 1998, Fergus Henderson wrote:
> > 
> > > +A @samp{:- implementation.} declaration indicates
> > 
> > s/A /An /
> 
> It's pronounced "a colon-dash implementation declaration".
> 
Is that to distinguish it from some other form of implementation
declaration?  For what it's worth, my first intuition was that
Peter was right.

Cheers,
Mark