@SimplyBeautifulArt @amWhy @user400188 @shredalert: See this post and comments for a recent clear illustration of why Phil SE is unsuitable for philosophy of mathematics. See also this immoral post that I've flagged but is still having a fiel day on Phil SE!
"Outside definitions" are neither necessary nor available. Everything you know and can speak about belongs to your domain of experience or can be reached by combining elements of this domain.
When you start your life, you have not many words except lala and mama or so. Every object you have to l...