Statistics Comparer

It is good to have partners (or rivals) in any competitions. Rivals can give you strong motivations to improve yourself. One of the motivations can be: "to solve any problem that your rivals solves, just to stay ahead from your rivals :)".

Using set manipulations you can merge your statistics with your partners and compare it with other groups of rivals :D interesting, isn't it? See the following examples. Later on, the variables A,B,C,D,E should be replaced by the usernames of the users.

The available operators are: union +, subtraction -, intersection &, and brackets ( ) to force operator precedence.

Expression: