# [texhax] package

Philip TAYLOR P.Taylor at Rhul.Ac.Uk
Tue Nov 29 16:49:31 CET 2005

No, I saw no answer, but now that the problem is well-defined
the solution should be trivial, requiring nothing more than
a couple of nested boxes each with a single rule. Ah, reading
on, I see you arrived at exactly that conclusion !

** Phil.
--------
Uwe Lück wrote:

> Nice ... no proposal yet? Joanne Snow's? [continued below]
>
> At 15:38 23.11.05, Philip TAYLOR wrote:
>
>> Joanne Snow asked the same question in 2003,
>> but she did gloss the half-box :
>>
>> > Does anyone know how to type the half-box that that is used in
>> actuarial
>> > or financial math as part of the subscript for the present value of an
>> > annuity?  I want to be able to type a subscript n with a half-box
>> (top
>> > and right side)"  around the n.  I have 2 awkward methods--neither of
>> > which satisfies me.
>> > Thanks.  Joanne Snow
>>
>> Philip Taylor
>> --------
>> Uwe Lück wrote:
>> > Hello Wickes,
>> >
>> > At 07:17 21.11.05, Wickes Robbertse wrote:
>> >
>> >> I'm trying to find a command or package to facilitate actuarial
>> >> notation in LaTex, i.e. for an ordinary annuity a_n the n is placed in
>> >> a halfbox.
>
>
> I've got this by boiling down LaTeX's \fbox:
>
> \makeatletter
> \newcommand{\annuity}[2]{%
>   \ensuremath{#1_{%
>     \setbox\@tempboxa\hbox{%
>       $\m at th\scriptstyle#2$\hskip\p@}%
>     \hbox{% !?!
>         \vbox{%
>           \hrule
>           \hbox{%
>             \vbox{%
>               \vskip\p@
>               \box\@tempboxa}%
>             \vrule}}}}}}
> \makeatother
> \begin{document}
> \annuity{a}{n}
>
> This may be my first proposal here that I've tested.
> The \hbox marked with !?!' seems to improve how the
> rules meet -- curiously.
>
> It is like a \fbox with \fboxsep=1pt -- I have no idea
> whether this is appropriate.
>
> More simple:
>
> \makeatletter
> \newcommand{\annuity}[2]{%
>   \ensuremath{#1_{%
>     \hbox{%
>       $\m at th\scriptstyle\overline{#2\hskip\p@}$\vrule}}}}
> \makeatother
> \begin{document}
> \annuity{a}{n}
>
> So I have two prosals as well. Again, \hskip\p@ is arbitrary.
> It would be nice if the skip amount would be the distance
> from overline rule to letter, i.e., 3 times the default rule
> thickness as in TeXbook p. 443 Rule 9 -- I don't know how
> to call the font under LaTeX of which it is \fontdimen8.
> And it should be ensured that the \vrule is as thick as
> the overline rule. And I cannot see from here at home
> whether the two rules meet apropriately.
>
> Good luck,
>   Uwe Lueck.
>

`