Lists

List L = x0  x1  x2  x3 ... xn-1     n =  # elements
If a list is ordered than the key of xi-1 <= the key of xi for all i where
0 < i < n.
The sort symbol <= can be replaced by >= or any other function that
determines ordering in the keys.
An unordered does not have this restriction.

Functions:
access(L, i)   		returns xi
length(L)  		returns n
concat(L1, L2)		returns a new list with L2 concatenated on to L1
createEmptyList()	returns a newly created empty list
isEmptyList(L)		returns true if L is empty and false if it is not
searchFor(L, key)	returns i where the key of xi = key
remove(L, i)		returns a list with xi removed
			the old xi+1 is now xi, etc.
inserti(L, i, x)	returns a list with x inserted as xi  
			the old xi is now xi+1, etc.
insert(L, x)		returns a list with x inserted anywhere 
			if L is unordered at the proper location (say xi)
			if L is ordered the old xi is now xi+1, etc.
sort(L)			returns the list in sorted order