modified:   3-multiinsertR.scm
	modified:   3-subst2.scm
	modified:   4-<.scm
	new file:   4-=.scm
	modified:   4->.scm
	modified:   4-division.scm
	new file:   4-factorial.scm
	new file:   4-multi.scm
	modified:   4-plus.scm