7. Now the user returns to use the knowledge that the 1 at 4,3 cannot
be touching any more mines. Left clicking on 4,2 has revealed a cell
with score 0. When this happens the program automatically reveals all
the cells around the 0, and if any of those are 0, it reveals their
neighbours too, and so on. Hence we reach the position shown here. What
next? Well, the 1 at 3,3 is also already touching a flag so the hidden
cell at 2,2 can be revealed.
8. That cell turns out to be a 3. Now the user notices that the 1s at
1,4 and 2,4 are not touching any flags and are only touching one
hidden cell. This cell must be a mine.
9. The cell has been flagged and now it is easy to finish.
10. The 1 at 2,3 is touching a flag so the user has safely uncovered
the hidden cell touching it to reveal a 3.
Now both the 3s need another two mines and the two 1s each need a mine.
11. The user has flagged one of the remaining cells. The program
recognises that there's one more mine to locate and only one more
cell, so it declares success and all the smileys look very
happy. Whoopee!
