Hi Paul and Uwe,

>>>>> Paul Nelson <ultrono@gmail.com> writes:
> As for the "always-align t" case, there are still some natural "broken"
> examples, as you know:
> #+begin_src latex
> \begin{equation*}
>   g = \begin{pmatrix}
>         a & b \\
>         c & d \\
>       \end{pmatrix},
>       \quad
>       h = \begin{pmatrix}
>             x & y \\
>             z & w \\
>           \end{pmatrix}.
> \end{equation*}
> #+end_src
> #+begin_src latex
> The matrix $\begin{pmatrix}
>               a & b \\
>               c & d
>             \end{pmatrix}$ has determinant
>             \begin{equation*}
>               a d - b c.
>             \end{equation*}

>             The matrix $\begin{pmatrix}
>                           a & b \\
>                           c & d
>                         \end{pmatrix}$ has determinant
>                         \begin{equation*}
>                           a d - b c.
>                         \end{equation*}

>                         The matrix $\begin{pmatrix}
>                                       a & b \\
>                                       c & d
>                                     \end{pmatrix}$ has determinant
>                                     \begin{equation*}
>                                       a d - b c.
>                                     \end{equation*}
> #+end_src

I've been gradually inclined to the attached approach. Namely, align "&"
as well as \end{foo} relative to beg-col, not beg-pos. In this way, the
above examples turn into
----------------------------------------------------------------------
\begin{equation*}
  g = \begin{pmatrix}
    a & b \\
    c & d \\
  \end{pmatrix},
  \quad
  h = \begin{pmatrix}
    x & y \\
    z & w \\
  \end{pmatrix}.
\end{equation*}
----------------------------------------------------------------------
and
----------------------------------------------------------------------
The matrix $\begin{pmatrix}
  a & b \\
  c & d
\end{pmatrix}$ has determinant
\begin{equation*}
  a d - b c.
\end{equation*}

The matrix $\begin{pmatrix}
  a & b \\
  c & d
\end{pmatrix}$ has determinant
\begin{equation*}
  a d - b c.
\end{equation*}

The matrix $\begin{pmatrix}
  a & b \\
  c & d
\end{pmatrix}$ has determinant
\begin{equation*}
  a d - b c.
\end{equation*}
----------------------------------------------------------------------

This patch indents as
\begin{equation}
  n u m=\left[\begin{array}{ll}
    2 & 25
  \end{array}\right]
\end{equation}
, not the form Paul proposed
\begin{equation}
  n u m=\left[\begin{array}{ll}
                2 & 25
  \end{array}\right]
\end{equation}
. Maybe Uwe doesn't like the former indentation, but it is more similar
to the behavior of other (non-tabular type) environments.

> With a bit more massaging, it should be possible to avoid these.  I had in
> mind modifying LaTeX-indent-level-count (or the block surrounding where it
> is called) in \end{TABULAR} cases, adjusting by the difference between the
> matching \begin and its beginning of line.

A similar idea crossed my brain, too. The best position to modify would be
`LaTeX-indent-calculate-last'.
It would make the indent algorithm more complex, so I began to search
for more simple solution.

Regards,
Ikumi Keita
#StandWithUkraine #StopWarInUkraine