what fallacy is this? If A does not equal B, B is false

Well that makes no sense at all.
What does it have to do with politics ?

Very difficult to say given the amount of information.

You may well be asking about identity theory and as such you are asking a philosophical question. If this is the case then I assume you are saying if x and y are distinct, then there must be some property(s) that allows us to distinguish between x and y. In other words x has some property not found in y or vice versa.

If this is the case then I would say there is no fallacy involved. Y is not void.

An actual example or more detail would be helpful.


Tut