====== HW4 ======
In this week, we discussed Lebesgue integral, using the intuitive picture of undergraph. 

0. write a short summary about Lebesgue integral, e.g how we define it, how does it compare with Riemann integrals.  Share it on your homepage.

1. read Tao Analysis-II, 7.5 and 8.1. 

2. {{ :math105-s22:hw:pugh.pdf |Pugh}} Ex 25, 28