Add the supplementary interpretation to Exercise 2.60.

Included are the following 2 files:

	Exercise_2.60.pdf
	Exercise_2.60.tm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China
Add Example: Sets as ordered lists.

Included are the following 2 files:

	Set-Ordered_Lists.scm
	Test_of_Set-Ordered_Lists.scm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China
Add Example: Sets as binary tree.

Included is the following file:

	Sets-Binary_Trees.scm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China
Update my answer to Exercise 2.60.

Included are the following 2 files:

	Exercise_2.60.pdf
	Exercise_2.60.tm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China