This is a class at NTU by the professor Jhih-Huang Li. The main reference is on the course website.
Set Theory, Real Numbers, and the Cardinality of Sets. Note
Selected Solutions to Homework 2. Note
Selected Solutions to Homework 3 and Hints to Homework 4. Note
Selected Solutions to Homework 4. Note
Selected Solutions to Homework 5 and 6. Note
Absolute Values on Rational Numbers and Ostrowski’s theorem. Note
Selected solutions to Homework 7 and Hints to Homework 8. Note
Selected solutions to Homework 8 and Hints to Homework 9. Note
Selected solutions to Homework 9 and Hints to Homework 10. Note
Selected solutions to Homework 10 and Hints to Homework 11. Note
Selected solutions to Homework 11 and Hints to Homework 12. Note
Selected solutions to Homework 12 and Hints to Homework 13. Note
Selected solutions to Homework 13 and Partial Solutions to Homework 14. Note