gfnさんへのリプライです: https://twitter.com/nekketsuuu/status/1049646583426383872

main.pdf

main.saty

@require: stdjabook
@import: matrix

document (|
  title = {\SATySFi;で行列};
  author = {\@nekketsuuu};
  show-title = false;
  show-toc = false;
|) '<
  +math(${
    \matrix!([
      [${1}; ${2}; ${3}];
      [${4}; ${5}; ${6}];
      [${7}; ${8}; ${9}];
    ])
  });
>

matrix.satyh

@require: math
@require: table

module Matrix : sig
  direct \matrix : [(math list) list] math-cmd
end = struct
  let-math \matrix elmss =
    let body = text-in-math MathInner (fun ctx -> (
      let cellss = fun t -> List.map (List.map (fun elm -> t#c {${#elm}})) elmss in
      let grf = fun _ _ -> [] in
      read-inline ctx {\tabular(cellss)(grf);}))
    in ${\paren{#body}}
end