The question is getting at an essential element of the charge, i.e. applicability of the law or statute.

How can someone be said to violate a code if the code does not apply?

As such, it is essential to prove (with evidence) that the law applies.

It is not good enough to merely assert a claim. Much like your claim that the question is argumentative. How is it argumentative if the very nature of any validity to a claim is having evidence or facts that back up that assumption?

As an aside, give me the explanation for the origin of English common law and stare decisis.

Edit:

It seems kind of pointless, because then youll say 'well, you cant prove that applies'.

It's not pointless because that's exactly what I am saying. No evidence exists as to the applicability of the law. Ergo, it doesn't apply.

My kid brother and I used to play the same game when i was 7. He would say something, and i would say "prove it" then he would say something to prove it, and i would say 'prove it', then he would say something to prove it, and i would say 'prove it'.

The problem with your anecdotal story is that you are asking to continually prove statements, whereas with this line of questioning, you end with evidence and facts.