@Albuquerque,
Yes, I am absolutely making an argument ad authority. You don't learn mathematics based on watching youtube videos... especially if you aren't willing to change your understanding when you are wrong.
I am actually making three arguments.
1. People who have studied mathematics understand the subject better than people who base their understanding on youtube videos (this is argument ad authority). Studying mathematics means lots of time learning, solving problems and getting feedback from professors and peers.
2. You are showing a basic misunderstand of the difference between numbers and sets (this is an argument of you clearly not understanding).
3. You are stating that
the number 10 is equal to the number 6. (this is an argument of you having a clear contradiction in your reasoning and still being unwilling to change your mind).