1,031
edits
Changes
→Border matrices with {{cmd|startbbordermatrix}}
\stopformula
</context>
A second version, with {{cmd|startmatrix}} and using {{cmd|TT}} to define indexes.
<context source="yes">
\startformula
\startmatrix[left={\left(},right={\right)}]
\TT {\bi col 1} \TT {\bi col 2} \TT {\bi col 3}\NR
\NC a_{11} \NC a_{12} \NC a_{13} \NR
\NC a_{21} \NC a_{22} \NC a_{23} \NR
\NC a_{31} \NC a_{32} \NC a_{33} \NR
\stopmatrix
\stopformula