I have a terribly short question:
Is there a way to define a pure mathematical set?
I tried a bit of googling, but the word "set" has two meanings and the other one (as in setting) as by far more dominant and I couldn't find any reference to mathematical sets in Mathematica.
As for the application, I would like to be able to define two sets
B and test whether the two sets are the same or not, namely have the same elements.