References ii
1. Problems on Sets,Sequences and Limits 1
1.1. Elementary Technique 1
1.2. Applications of the Stolz theorem 11
2. Inequality 14
3. Orders Estimate of Innitesimal 20
3.1. Notations and Examples 20
3.2. Exercises and homework 23
4. Application of Innitesimal: Wallis ...