Add my answer to Exercise 4.58.

Included are the following 2 files:

	Exercise_4.58.scm
	ch4-query.scm

Thank you!
							Lawrence X. Amlord
							  Mar 23rd, 2014
							  Xi'an, China
Add my answer to Exercise 4.59.

Included are the following 2 files:

	Exercise_4.59.scm
	ch4-query.scm

Thank you!
							Lawrence X. Amlord
							  Mar 25th, 2014
							  Xi'an, China
Update my answer to Exercise 4.55.

Newly added is the following file:

	ch4-query.scm

Thank you!
							Lawrence X. Amlord
							  Mar 25th, 2014
							  Xi'an, China