Add my answer to Exercise 1.15.

Included are the following 3 files:

	Exercise_1.15.pdf
	Exercise_1.15.scm
	Exercise_1.15.tm

If you find out any mistake in my solution here, please contact me at
informlarry@gmail.com.

Thank you!
							Lawrence R. Amlord
							   Apr 26, 2013
							   Xi'an, China
Add my answer to Exercise 1.16.

Included are the following 3 files:

	Exercise_1.16.pdf
	Exercise_1.16.scm
	Exercise_1.16.tm

Gosh! Exercise 1.16 isn't easy at all to deal with if you try to describe
the your motivation in detail.

Awared of my answer here might be imperfect, I would like to appreciate
anybody who pointing out the flaw. If you find out any mistake here, please
contact me at informlarry@gmail.com.

Thank you!
							Lawrence R. Amlord
							   Apr 27, 2013
							   Xi'an, China