Oh ok understood 
Well I thought that a new version of a gem is
better
then the previous one, so why Arel update at 2.1.1 if Activerecord
doesn’t
use the new version? It seems to be useless…
I understood that maybe Activerecord doesn’t need or doesn’t care about
a
new version…
Well I don’t know what Arel is used to, but I’ve noticed the same
behaviour
for the gems RAKE and RACK for example… It should be important to use
a
new version of them no?
Anyway, i’ve understood your point, thanks again for ur time!!