1 Section 1. Basic concepts and definitions. Exercises page 18

1.1 problem 2
1.2 problem 3
1.3 problem 4
1.4 problem 5
1.5 problem 6
1.6 problem 7
1.7 problem 8
1.8 problem 9
1.9 problem 10
1.10 problem 11
1.11 problem 13
1.12 problem 14
1.13 problem 15
1.14 problem 16