*Combinatorial Mathematics* - Fall 2007 Typos

This page lists the typographical errors that have been discovered in
the Fall 2007 pre-publication version of
*Combinatorial Mathematics*, by Douglas B. West.
This page is of interest only to those persons having a copy of this draft,
particularly the students in my course, other users of the text, and reviewers.
Please send comments and corrections on the book to *west @ math.uiuc.edu*.
Contributors are noted in parentheses.
Please do not send comments about incorrect page numbers in the index
(and note that all page numbers there are odd for \TeX nical reasons);
however, I do want to know of missing terms that should be added to the index.
## Category 1: Mathematical typos/corrections to text

- p30 - Exercise 1.1.43: The conclusion does not hold for all
*m*.
I believe it holds when *m* is prime.
- p87 - Lemma 2.2.16: The index of summation in the statement should be
"
*n*", not "*k*" (Sayan Dissanayake)
- p74 - Exercise 2.1.21: the first equation should not have the last term
on the right (Art Benjamin)
- p95 - Exercise 2.2.26: "
*F*_{k}" should be
"*A*_{k}"
- p117 - Example 3.1.11: In the last line of the example, the factor
*x*^{k} is missing from both summands (Hsueh-Yi Chen)
- p128 - Exercise 3.1.30: "
**S**_{n}"
should be "**S**_{2n}"
- p144 - Exercise 3.2.43: "3.2.23" should be "3.2.16"
- p204 - Theorem 4.1.31: In the figure, the subscripts for the vertices
of
*Y* on the right are wrong; *\sigma'(3)* and *\sigma'(1)*
should be switched
- p368 - Exercise 7.1.22: "if a" should be "every"
- p422 - Exercise 8.1.23: the numerator should be the maximum of
*\delta(H)+1* over subgraphs *H* of *G*
- p479 - Exercise 9.1.20: delete "05F"
- p584 - Theorem 11.1.12: in the second line, the denominator should be 4,
not 3
- p617 - Exercise 11.3.10: inside the floor function should be
*rs/(r+s-1)*
- p952 - Theorem 17.2.15: the statement and argument are incorrect.
The correct lower bound is the ceiling of
*\sqrt{n-1}*, which is
achieved by the polarity graph
- p953 - just after Proposition 17.2.16: the statement is not correct.
The number of edges in the polarity graph is
*q(q+1)²/2*, and
it differs from the upper bound by *q+1*

## Category 2: Comments, clarifications, and cross-references

## Category 3: Minor typos and corrections

Note: Corrections involving addition, deletion, or alteration of one
punctuation mark may be implemented without being listed here.
Corrections to capitalization may also be omitted.
- p73 - Exercise 2.1.16: "Caroll" should be "Carroll"

Archive of corrections to earlier versions:
Fall 2006,
Fall 2005,
Fall 2004,
Fall 2003,
Fall 2002.