In the 9x9 grid (below), we find several numbers that represent islands
that must be connected forming a unique group connected by bridges.
Each bridge must have extremes in two distinct islands, being composed
by a unique line segment (horizontal or vertical), that cannot cross other
bridges, nor other islands. Any pair of islands may be connected by at most
two bridges. The number of bridges coming into any islands must match the
number associated to that island.

,-----------------------------------,
|         2       4           1     | 9 
|                                   | 
| 2           1       2           2 | 8 
|                                   | 
|     3           3                 | 7 
|                                   | 
|                                   | 6
|                                   | 
|     2               4       3     | 5
|                                   | 
| 4       4       4       2         | 4
|                                   | 
|                                   | 3
|                                   | 
| 1       2       3           2     | 2
|                                   | 
|     2                           3 | 1
'-----------------------------------'
  a   b   c   d   e   f   g   h   i  JCO#1 (Hashi; Proposed Aug 2, 2024)

(-1l)h9 means to that a single line from
(1)h9 to the left (l) must be drawn.
(=4l)e9 means that two parallel lines
to the left(4)e9 must be drawn.

It seems a better notation: (4)e9-(1)h9 and
(2)c9=(4)e9, respectively.

Island "j" that already have all its j bridges
is marked with *j*.

The solution to this puzzle is

,-----------------------------------,
|        *2*======4----------*1*    | 9 
|                 |                 | 
|*2*---------*1*  |  *2*---------*2*| 8 
| |               |   |           | | 
| |  *3*=========*3*  |           | | 7 
| |   |               |           | | 
| |   |               |           | | 6
| |   |               |           | | 
| |  *2*-------------*4*=====*3*  | | 5
| |                           |   | | 
|*4*=====*4*-----*4*=====*2*  |   | | 4
| |       |       |           |   | | 
| |       |       |           |   | | 3
| |       |       |           |   | | 
|*1*     *2*-----*3*---------*2*  | | 2
|                                 | | 
|    *2*=========================*3*| 1   JCO#1
'-----------------------------------'