EDIT: It appears the evidence I read about is a standard reference provided right here several moments :) I mentioned the proof by itself is considerably less handy than an define for me as I realize only "physics degree maths". 最简单的说法，即是在最原始的集合论。集合是把人们的直观的或思维中的某些确定的能够区分的对象汇合在一起，使之成为一个整体或称为单体，这一整体就是集合。 Auch kann... https://bihlmayermedia-bilder.com/1-advent/