Update the material of Project 1: The Game of Twenty-one.

Modified are the following 2 files:

	The_Game_of_Twenty-one.pdf
	The_Game_of_Twenty-one.tex

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Add my answer to Exercise 2.83.

Included is the following file:

	Exercise_2.83.scm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Add my answer to Exercise 2.84.

Included are the following file:

	Exercise_2.84.scm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Update my answer to Exercise 2.83.

Modified is the following file:

	Exercise_2.83.scm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Update my answer to Exercise 2.84.

Modified is the following file:

	Exercise_2.84.scm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Add my answer to Exercise 2.85.

Included are the following file:

	Exercise_2.85.scm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Add my answer to Exercise 2.86.

Included are the following 2 files:

	Exercise_2.86.pdf
	Exercise_2.86.tm

Thank you!
							Lawrence R. Amlord
							   Jul 31st, 2013
							   Xi'an, China
Add code of section 2.5.3.

Included are the following file:

	Example-Symbolic_Algebra.scm

Thank you!
							Lawrence R. Amlord
							   Aug 1st, 2013
							   Xi'an, China
Add my answer to Exercise 2.87.

Included are the following 2 files:

	Exercise_2.87.pdf
	Exercise_2.87.tm

Thank you!
							Lawrence R. Amlord
							   Aug 1st, 2013
							   Xi'an, China
Add my answer to Exercise 2.88.

Included are the following 2 files:

	Exercise_2.88.pdf
	Exercise_2.88.tm

Thank you!
							Lawrence R. Amlord
							   Aug 1st, 2013
							   Xi'an, China
Add my answer to Exercise 2.89.

Included are the following 3 files:

	Exercise_2.89.pdf
	Exercise_2.89.scm
	Exercise_2.89.tm

Thank you!
							Lawrence R. Amlord
							   Aug 1st, 2013
							   Xi'an, China