### Behavior of 'or'

Hello !

Here I have observed something in sage.

sage: (x == 1 or x == -3).full_simplify()

x == -3

sage: (x == -1 or x == -3).full_simplify()

x == -3

sage: (x == -1 or x == 3).full_simplify()

x == 3

sage: (x == -1 or x == -3).full_simplify()

x == -3

sage: (x == 1 or x == -3).full_simplify()

x == -3

I wish to know that why sage replies with the second argument. It is very necessary for me to understand this behavior of sage.

Many Thanks !