For problem 2 of the CLU homework, see the LISP chapter for what level
order traversal means.  The BinTree cluster of exercise 1 on page 266 is
found in /home/cs342/public/lib/clu/BinTree.clu.  (If you'd rather use
the code discussed in class, you may, it's in the same directory,
in the file Tree.clu .)  If you had trouble getting to this before,
try again, it should work now.
For problem 3 of the CLU homework, you don't have to program square root
(although you may do that as extra credit).
Problems 2 and 3 are due Wednesday, Problems 4 and 6 on Friday, Problem 8
is due on Wednesday, Mar 4.  (Note the change in due date for problem 8.)
Problem 8 will only be worth 10 points instead of 25, and if you don't do it
you won't get an incomplete, although it will hurt your grade some.

The new version of vocal-outline.l
fills in a representation for ChordComplex, shows
how to create a chord complex and how to use the ChordComplex to set the tenor.
To see the exact differences, execute:
   cd /home/cs342/public/lib/clu
   diff vocal-outline.l~ vocal-outline.l

There is no use for the operation ChordComplex$any-thirds?;
so you don't have to implement it.

The test cases contained in vocal-outline.l should generate output as follows:

-> (set song (voice-leading ic bl))
<userval>

-> (song-display song)
15
10
5
1
0
15
11
6
4
0
16
12
7
5
0
17
12
8
1
0
0

-> (set song (voice-leading ic hard-bl))
<userval>

-> (song-display song)
15
10
5
1
0
12
9
7
5
0
12
10
7
3
0
27
24
22
20
0
0

->