fix ambiguity comments in solution to Exercise 10.4-3.

Modified are the following 2 files:

	10.4-3.pdf
	10.4-3.tm

Thank you!
							Lawrence X. Amlord
							  Jun 7th, 2014
							  Xi'an, China
add solution to Exercise 10.4-4.

Included are the following 2 files:

	10.4-4.pdf
	10.4-4.tm

Thank you!
							Lawrence X. Amlord
							  Jun 7th, 2014
							  Xi'an, China