# Re: [NTG-context] Problem with \leqalignno

Hi Mingranina,

For displayed aligned formulas it is better to use \startalignâ€¦\stopalign,
instead of the plain TeX construction \leqalignno.
Please have a look at the following:

Best regards: OK
%%% begin align-equations.tex
\starttext

\placeformula
\startformula
\startalign
\NC c^2 \NC= a^2 + b^2  \NR[+]
\NC a^2 + b^2 \NC = c^2  \NR[+]
\NC d^2 \NC = e^2        \NR[+]
\stopalign
\stopformula

\startsubformulas[eq:Rel]
\placeformula
\startformula
\startalign
\NC c^2 \NC= a^2 + b^2  \NR[eq:a]
\NC a^2 + b^2 \NC = c^2  \NR[eq:b]
\NC d^2 \NC = e^2        \NR[eq:c]
\stopalign
\stopformula
\stopsubformulas
The relations (\in[eq:Rel]) are divided into three parts, but (\in[eq:c]) is
obvious.

\stoptext
%%% end align-equations.tex
> On 11 Sep 2016, at 03:00, Mingranina Gingranina <mingran...@gmail.com> wrote:
>
> Hello All,
>
> I am trying to compile the following example (from
> http://wiki.contextgarden.net/Math/Display) with context:
>
> \starttext
>
> \placeformula
> \startformula
> \leqalignno{c^2 &= a^2 + b^2  &\formulanumber{a} \cr
>           a^2 + b^2 &= c^2  &\subformulanumber{b} \cr
>           d^2 &= e^2        &\formulanumber\cr}
> \stopformula
>
> \stoptext
>
> but I get the following error message: {{{
> .
> .
> .
> tex error       > tex error on line 7 in file
> /home/user/math-example.tex: ! Undefined control sequence
>
> <argument> ...er {a} \cr a^2 + b^2 &= c^2 &\subformulanumber
>                                                  {b} \cr d^2 &= e^2 &\formu...
> \math_both_eqalign_no_normal ...ratchtoks \crcr #2
>                                                  \crcr \egroup \math_finish...
> l.7            d^2 &= e^2        &\formulanumber\cr}
>
>
> 1     \starttext
> 2
> 3     \placeformula
> 4     \startformula
> 5     \leqalignno{c^2 &= a^2 + b^2  &\formulanumber{a} \cr
> 6                a^2 + b^2 &= c^2  &\subformulanumber{b} \cr
> 7 >>             d^2 &= e^2        &\formulanumber\cr}
> 8     \stopformula
> 9
> 10     \stoptext
> 11
>
>
> ?
> }}}
>
> Am I doing something wrong? Any help would be gratefully appreciated.
>
> Thanks
> Mingranina
>
> ----------------------
> Luatex Version: 0.98.3
> ConTeXt Version: 2016.09.06 19:11 MKIV beta  fmt: 2016.9.9  int:
> english/english
> ___________________________________________________________________________________
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> Wiki!
>
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> ___________________________________________________________________________________

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________