Oooh ok ^^ than you I understand ! it's better like this lol. I'm not english so maybe it's just my own mistake.
The reason why I failed in this rule is in the tutorial. In explanations 6/10 and 8/10 you saied :
"the line only intersect...".
In first I understood this rule apply only if 2 lines intersect but not it they are more than 2.
That's why in my example I fill out numbers 5 and 4 because this line only intersect with 5 and 4.
I understand now ; if only 2 line intersect you know wich number to put inside. BUT if there are more intersection the rule stay the same ^^
So I can't judge with my non-English reading. But peraps the "only" explanation could be made more excplicit.
Hope it's help ;-) I know feedback is important and most people never notify when they find problems.