Add my answer to Exercise 4.30.

Included are the following 6 files:

	Exercise_4.30.pdf
	Exercise_4.30.tm
	Lazy_Evaluator_(Cy's_Variant).scm
	Lazy_Evaluator_(Original).scm
	Test_for_Lazy_Evaluator_(Cy's_Variant).scm
	Test_for_Lazy_Evaluator_(Original).scm

Thank you!
							Lawrence X. Amlord
							  Feb 25th, 2014
							  Xi'an, China
Add my answer to Exercise 4.31.

Included are the following following 2 files:

	Test_for_Upward-Compatible_Evaluator.scm
	Upward-Compatible_Evaluator.scm

Thank you!
							Lawrence X. Amlord
							  Feb 26th, 2014
							  Xi'an, China