# [texhax] very long nested expressions in math-mode

Douglas Lewan d_lewan2000 at yahoo.com
Tue Oct 18 20:35:12 CEST 2005

You might want to consider this reference:

http://research.microsoft.com/users/lamport/proofs/proofs.html

--- Torsten Anders <torstenanders at gmx.de> wrote:

> Dear all,
>
> Firstly, I should mention that I am new to this
> list. I read the FAQ
> and quite some docomentation to find an answer to my
> problem, without
> success unfortunately. Nevertheless, I apologise in
> case I missed
> something obvious.
>
> I want to transform program source examples into
> mathematical notation
> in Latex (tetex, i.e. incl. AMS packages), because
> that way the
> examples become more concise and better to
> communicate. Because the
> source is based on functional and logic programming,
> the available
> algorithm packages are less suited -- the result is
> as procedural programming. Instead, I would prefer
> to write plain math
> expressions.
>
> In short, my problem is that I need to write rather
> long expressions
> (e.g. highly nested and with long variable names for
>
> comprehensibility). Thus, line breaks are
> inevitable. Naturally, the
> continued expression should be indented to indicate
> the nested
> structure of the expression. That is, I don't what
> to mechanically
> indent by a certain amount (e.g. by \quad), but the
> indentation should
> depend on the indentation depth of the surrounding,
> e.g., function
> call. For instance, a short dummy example may read
> like this:
>
> xs = find(map([1, 2, 3],
>                          f : f(x) = x^3),
>                isEven)
>
> The most easy way to do something like this is
> probably to use
> mono-space fonts in some verbatim environment.
> However, I would prefer
> to write my example in Latex's math mode: e.g., I
> would prefer to use
> signs like \vee, \wedge, \bigwedge etc.
>
> To avoid getting lost in my own long Latex examples,
> I would like to
> define some suitable Latex command, e.g., to get the
> example above I
> would like to write something like
>
> $xs = \Apply{find}{\Apply{map}{[1,2,3], \\ f : f(x) > = x^3}, \\ isEven}$
>
> So far I did not find a way to define \Apply as
> above and get a
> suitable output. In the following, I present a few
> of my attempts to
> set my examples. However, none of what I came up
> with so far is really
> satisfying. Perhaps anybody here can help me..
>
> Here comes my first naive attempt to define \Apply:
>
> \newcommand{\Apply}[2]{\ensuremath{#1 (
> \begin{aligned}[t] #2
> \end{aligned} ) }}
>
> which is called
>
> $xs = \Apply{find}{&\Apply{map}{&[1,2,3], \\ &f : > f(x) = x^3}, \\ > &isEven}$
>
> The additional '&' makes the code slightly less
> actual problem is that everything after the aligned
> environment (i.e.
> the comma and the cloing parenthesis) 'go back' on
> the original line
> like
>
> xs = find(map([1, 2, 3],	 ),)
>                          f : f(x) = x^3
>                isEven
>
> Next try:
>
> \newcommand{\Apply}[3]{\ensuremath{#1 (
> \begin{aligned}[t] #2 ) #3
> \end{aligned} }}
>
> $xs = \Apply{find}{&\Apply{map}{&[1,2,3], \\ &f : > f(x) = x^3}{,} \\ > &isEven}{}$
>
> This results in the desired output, but for complex
> examples with
> parenthesis/brackets/curly braces in the third
> \Apply argument this
> becomes very hard to read and the editor (i.e.
> emacs) can't help
> anymore.
>
> To avoid the problem that after a box -- which
> starts at the current
> line but introduces some line breaks -- the current
> line is _not_
> continued I tried to center the whole expression:
>
> \newcommand{\Apply}[2]{\ensuremath{#1 \left(
> \begin{aligned} #2
> \end{aligned} \right) }}
>
> $xs = \Apply{find}{&\Apply{map}{&[1,2,3], \\ &f : > f(x) = x^3}, \\ > &isEven}$
>
> The structure of the resulting expression is still
> the code is also more easy to write. However, this
> layout can also
> of a function call
> the parenthesis look more like a binom (and reducing
> the gap between
> the function name and the parenthesis does not
> really overcome that).
> :-P
>
> Does anybody have a better idea how to set very long
> nested
> expressions? Any help is most appreciated!
>
> Best wishes,
> Torsten
>
> --
> Torsten Anders
> Sonic Arts Research Centre
> Queen's University Belfast (UK)
> www.torsten-anders.de
>
> _______________________________________________
> TeX FAQ: http://www.tex.ac.uk/faq
> TeX newsgroup: