Hi Danilo,
I found this surprising only because I always thought that the same rules that hold for the first bin of a TH1 (“lower edge is included”) and the last (“upper edge is excluded”) were also valid for all other bins. Now I see that this is probably not the case, and so I was just looking for a confirmation about it from ROOT developers, before eventually suggesting to explicitly mention it in the TH1 documentation.
Cheers,
Fabio