add solution to Exercise 4.63.

Included is the following file:

	Exercise_4.63.scm

Thank you!
							Lawrence X. Amlord
							  Jul 17th, 2014
							  Xi'an, China
add solution to Exercise 4.64.

Included are the following 2 files:

	Exercise_4.64.pdf
	Exercise_4.64.tm

Thank you!
							Lawrence X. Amlord
							  Jul 21st, 2014
							  Xi'an, China