Hans Aberg

7. Juli 2015 21:11

On 7 Jul 2015, at 20:17, Wolfgang Schuster <schuster.wolfgang@gmail.com> wrote:

You can set the alignment for each column in a matrix with the align key.

FYI, the document amshelp.pdf says that AMS-LaTeX environments align, align*, and aligned, can have multiple alignments, and gives this example:
\begin{align*}
  K &\approx G * H&   i&= j+k&  B &\subset C\\
  H &\approx A_{0}*B_{0}&  i’&= j’+k’&  C &= D\cap E\\
  G &\approx \coprod_{\alpha\in A} L_{\alpha}&  i’’&=j’’+k’’& A &= D \cup E
\end{align*}
which is typeset so that 'K &\approx G * H’ is one equation aligned on the ‘&’ with the others below, followed by 'i&= j+k’ in the next column.

So the ampersands have multiple functions here, it seems: alignment and separating columns.

Translating into ConTeXt, one might have (pseudocode):
\startformula
  \startalign
    \NC K \NA \approx G * H \NC  i\NA= j+k \NC B \NA \subset C \NR
    \NC H \NA \approx A_{0}*B_{0} \NC   i’\NA= j’+k’ \NC   C \NA = D\cap E\NR
    \NC G \NA \approx \coprod_{\alpha\in A} L_{\alpha}
      \NC   i’’\NA =j’’+k’’ \NC  A \NA = D \cup E \NR
  \stopalign
\stopformula
where I have introduce a symbol \NA for alignment.