**Key Notes**:

- Rational Numbers Q eg. 1/2, … Complete but non Continuous.
- Irrational numbers eg. $latex sqrt {2}$
- Real number is Complete and Continuous
- Dedekind Cut

The Proof of “0.999… = 1” by using Set Theory :

$latex A subset B$

and

$latex B subset C$

$latex implies A = B $