0.999....=1

[Peh]

Teeqoz said:

Peh said:

You already did. You defined 0.9999... as x. 0.999 could be also called milk if you want and milk equals 1

Nearly every single mathematical proof there is starts with stating something equivalent to "if x = 0.999... then:". If that is a valid reason to say my proof is invalid, then oh boy, we have to throw a lot of mathematics out the window! Also, the user I quoted was asking about the fraction proof, where I didn't use x at all.

Well then, what definition has 0.9999... ? What kind of number is that and what rules does it have?