Re: [Groff] EQN documentation

[Ted Harding]

On 16-Jan-11 12:29:58, Ralph Corderoy wrote:
> 
> Hi Cedric,
> 
>> For a useful you have too google for the original UNIX manpages which
>> are, by the way, only hosted very sparely over the internet. And even
>> there the documentation of EQN appears to be incomplete.
> 
> Are you aware of the original papers on eqn?  They're linked to from
> http://troff.org/papers.html
> 
>     http://www.kohala.com/start/troff/v7man/eqn/eqn2e.ps
> 
> Cheers,
> Ralph.

and, with reference to Cedric's original query:

  Occasionally I stumble over features such as the "grad" operator,
  but I find out about those only by accident. So far, I've not
  found any reference which mentions, even remotely, that something
  like a shortcut for the Nabla exists.

note that in Section 23 ("Keywords, Precedences, Etc.") of Ralph's
reference that the symbol in question is listed both as "del" and
as "grad". Both of these are recognised by GNU 'eqn'. However, the
keyword "nabla" is not built in. But if you want to use it, you can
define it for yourself. Thus all of the following will work:


.EQ I
bold F ~=~ del phi
.EN

.EQ I
bold F ~=~ grad phi
.EN

.EQ I
define nabla %del%
bold F ~=~ nabla phi
.EN


Hoping this helps!
Ted.

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Date: 16-Jan-11                                       Time: 13:01:49
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