Incidence matrix according to symbol extension

o3x:s3s6s = rect( x3o:s3s6s )   (N,M → ∞)

3NM |   2   4   4 |   3   2   2   6  2 |   4 1 2
----+-------------+--------------------+--------
  2 | 3NM   *   * |   1   0   2   0  0 |   2 0 1  underneath tips of former lacing trigs of 3pyrs
  2 |   * 6NM   * |   1   0   0   2  0 |   2 0 1  underneath base-vertex of former lacing trigs of 3pyrs
  2 |   *   * 6NM |   0   1   0   1  1 |   1 1 1  underneath vertices of other trigs
----+-------------+--------------------+--------
  3 |   1   2   0 | 3NM   *   *   *  * |   2 0 0  rect of former lacing trigs of 3pyrs
  3 |   0   0   3 |   * 2NM   *   *  * |   1 1 0  rect of former other trigs
  3 |   3   0   0 |   *   * 2NM   *  * |   1 0 1  underneath tip of former 3-pyr
  3 |   0   2   1 |   *   *   * 6NM  * |   1 0 1  underneath base-vertex of former 3-pyr
  6 |   0   0   6 |   *   *   *   * NM |   0 1 1  underneath vertex of former trat
----+-------------+--------------------+--------
  6 |   3   6   3 |   3   1   1   3  0 | 2NM * *  oct
 3M |   0   0  6M |   0  2M   0   0  M |   * N *  that
 6M |  3M  6M  6M |   0   0  2M  6M  M |   * * N  snathat