©

Incidence matrix

(N,M → ∞)

NM   *   * |   4   0   0   0 |  2  2  0  "head-vertices" of P
 * 4NM   * |   0   1   1   1 |  1  1  1  "arm-vertices" of P
 *   * 4NM |   1   0   1   1 |  1  1  1  "leg-vertices" of P
-----------+-----------------+----------
 1   0   1 | 4NM   *   *   * |  1   1  0  DP (slanted)
 0   2   0 |   * 2NM   *   * |  1   1  0  DP (horizontal)
 0   1   1 |   *   * 4NM   * |  1   0  1  AD
 0   1   1 |   *   *   * 4NM |  0   1  1  AP
-----------+-----------------+----------
 2   4   4 |   4   2   4   0 | NM   *  *  D = {10/3}
 1   2   2 |   2   1   0   2 |  * 2NM  *  P = {5}
 0   M   M |   0   0   M   M |  *   * 4N  A = {∞}