real number既問題

In fact, they are not number.
So, there are not real number.

But in the extended real line, both infinity are included as objects at the end on the line of both sides

The reader should note once again that the symbol +無限 is not mean to denote the name of a specific number. It is a historical term which has remained in the language.

Handbook of Applicable Mathematics, Vol. IV: Analysis p.9-10