I'm pretty sure that I asked about learn ages back, but I couldn't find 
any reference to it in the archives. So, I thought I would close the 
possibly imaginary loop on it. Cuz, I figured it out, and it may prove 
useful to others or with my track record, even myself in the future :).

Learn works fine in v7. It just needs to be properly installed. The 
command is there already, so you may not need to follow all of the steps 
below, but it doesn't hurt:

I did this as root, but it could possibly be done as another user, I'm 
not sure.

    cd /usr/src/cmd/learn
    make
    make lessons
    make play; make log

That's it. make will complain about missing files that it tries to 
delete, but these can be safely ignored, since make then creates them 
anyway.

Here's the result run as a normal user:

    $ learn
    These are the available courses -
       files
       editor
       morefiles
       macros
       eqn
       C
    If you want more information about the courses,
    or if you have never used 'learn' before,
    type 'return'; otherwise type the name of
    the course you want, followed by 'return'.
    macros
    If you were in the middle of this subject
    and want to start where you left off, type
    the last lesson number the computer printed.
    To start at the beginning, just hit return.

    This script deals with the use of the "-ms" macro
    package to produce Bell Laboratories style documents.
    Before trying it, you should be familiar with the
    editor.  To test that, please enter the file
    typed below, exactly as is, into file "decl".  Then
    type "ready".

    .PP
    When in the course of human events, it becomes
    necessary for one people to dissolve the political bands which have
    connected them with another, and to assume among the
    powers of the earth the separate and equal station to which
    the laws of Nature and of Nature's God entitle them, a decent
    respect to the opinions of mankind requires that they should
    declare the causes which impel them to the separation.
    $ ed decl
    ?decl
    a
    .PP
    When in the course of human events, it becomes
    necessary for one people to dissolve the political bands which have
    connected them with another, and to assume among the
    powers of the earth the separate and equal station to which
    the laws of Nature and of Nature's God entitle them, a decent
    respect to the opinions of mankind requires that they should
    declare the causes which impel them to the separation.
    .
    w
    410
    q
    $ ready

    Good.  Lesson 1.1a (1)

    When you have some document typed in "-ms" style,
    you run it off on your terminal by saying:

       nroff -ms file

    where "file" is the name of the file it is on.  For example,
    the file "decl" in this directory is in a suitable format
    for running off this way.  Do so.  Then type "ready".
    $
    Interrupt.
    Want to go on?  n
    Bye.
    $

Pretty slick, really, once you realize that the $ prompt isn't really 
your shell, it's a shell within learn. Also, there's no learn manpage 
although there is a document in vol2 of the programmer's manual that 
describes the program. I couldn't figure out the canonical way to exit, 
so I just CTRL-DELETE on my mac, which I figure it CTRL-BREAK (^C?). 
That seems to work.

Oh, and according to /usr/src/cmd/learn/README, if you have any trouble:

Please report problems, bad lessons, etc., to
Brian Kernighan, MH 6021, 2C-518, or
Mike Lesk, MH 6377, 2C-572.  Thanks.

Enjoy, and happy New Year, folks!

Will