Status at 20110506(b)

Solved 2.3-4 on paper.
Solved P2-4a in my head.

Browse reading: 287/1144
Exercises up to 2.3-5
Exercises which are finished but not on paper: 2.3-7, P2.4a, 6.1-7, 6.2-3, 6.2-4, 10.1-6 and 10.1-7