MA 724, Combinatorics II, Nathan Reading

InstructorNathan Reading  
OfficeSAS 4118
Telephone919-515-3261. This is an office desk phone that does not accept text messages. Email is a much better way to reach me than phone.
Emailreading AT math DOT ncsu DOT edu
Course website You will be responsible for material on this site. You will be notified by email or in class when new information is posted on the site (except for regularly occurring changes like posting of assignments and solutions).
Class email listA class email list will be established within the first few days of the class. You will be responsible for any information emailed to the list. In particular, you should check your "unity" email account roughly every day.
Class SessionsTuesdays and Thursdays, 1:30 to 2:45 in SAS 1220.
Office hoursMondays, 11:00-12:00, Tuesdays, 3:30-4:30, Wednesdays 9:30-10:30, Thursdays 10:00-11:00, or by appointment.

This semester, I may occasionally have to miss the Tuesday office hour because we have job candidates coming in. This is the case on January 7. (I will be available after the 3:00-4:00 job talk.) Also, I will not be in town for the Monday, January 13 office hour.
Prerequisites MA 524 or permission of the instructor
Learning outcomes By the end of the course, the students will be able to:
- Write clear, precise and correct proofs in the area of geometric combinatorics;
- Compute invariants of polytopes;
- Perform Fourier-Motzkin elimination;
- Solve a linear programming problem;
- Create and/or identify a shelling order;
- Compute h- and f-vectors;
- Compute Stanley-Reisner rings and their Hilbert series;
- Construct an EL-shelling; and
- Apply all of these methods in unfamiliar combinatorial settings.
Text Lectures on Polytopes by Günter Ziegler.
We will cover most of the book.
Homework There will be homework assignments due most Thursdays at 4:00 PM.

You can expect each assignment to be posted to the assignments page by Wednesday a week before it is due. Please contact me immediately if you have any trouble getting the assignment (for example, if I have forgotten to post it).

Generally speaking, you need to turn in your homework on time. But I recognize that there is a lot to do and sometimes deadlines clash. So each student will be allowed turn in an assignment a day late up to two times in the semester, without penalty. (However, there may be some delay in getting your graded assignment back if you turn it in late.) If you find that you are needing to use these "late days" early in the semester, it is probably an indication that you need to adjust either your class schedule or your work routine or both.

You may collaborate on solving the assigned problems as long as everyone in the group gains a thorough understanding of the solution. I also highly recommend that not all your thinking on the problems be in groups. Furthermore, each student must write up the solution in their own words based on their own understanding.

All homework problems are asking for an answer in clear English (with math symbols allowed), giving a careful and correct explanation of how the problem is solved. Imagine you are writing to a mathematically literate person who does not know how to solve the problem. The balance of prose vs. symbols required in the solution will vary greatly, from 2-3 words followed by a symbolic or numerical calculation to several paragraphs of prose with few or no symbols. Part of the point of this course is for the student to develop judgement about how to explain mathematics. Some things that could cause you to be marked down are: using vague language; using words like "obviously" or "clearly" to hide the lack of an explanation; relying too much on the grader to figure out "what you meant;" rambling or extraneous prose that fails to focus concisely on the core issue.

Here are the homework assignments.

Here are some Comments and answers on homework assignments and tests.

Midterm exams  There will one midterm exam in class. The date for the exam is Thursday, March 5.
Final Exam  The final exam is Tuesday, May 5, 1:00--4:00 p.m., in the usual room.
Grading  The components of your grade are:
Homework: 50% of grade
Midterm: 20% of grade
Final exam: 30% of grade.
Wolfware  I will be keeping track of your grades on Moodle (Wolfware), so you will be able to see them as soon as they are posted.
Succeeding in this course  There is no shortcut to learning this material. You will need to engage intellectually with the lectures, the book, and the homework. And you will need to organize your time so that you can start the homework early.

If you are working hard and still struggling, please get in contact with me and we can talk.
N.C. State Polices, Regulations, and Rules Students are responsible for reviewing the NC State University polices, regulations, and rules which pertain to their course rights and responsibilities:

Equal Opportunity and Non-Discrimination Policy Statement
Code of Student Conduct
Grades and Grade Point Average
Credit-Only Courses
Policy on Attendance and Make-ups  Attending every lecture (in its entirety) is considered part of the course requirement. No provisions will be made for students to make up missed work or tests except as spelled out in the University's attendance regulation available at .

Policy on Incompletes  Incompletes are not offered except in cases where special circumstances (such as outlined in the attendance regulation mentioned above) make it impossible for a student to complete the course. Even in these special circumstances, incompletes will not be offered unless the student was in a position to pass the class before the special circumstance arose. In particular, incompletes cannot be used as a way to "bail out" when a student feels that they cannot pass the course or feels they cannot do all the work they put off until the end of the semester.
Statement for students with disabilities  Reasonable accommodations will be made for students with verifiable disabilities. In order to take advantage of available accommodations, students must register with the Disability Services Office at Suite 2221, Student Health Center, Campus Box 7509, 919-515-7653. For more information on NC State's policy on working with students with disabilities, please see Academic Accommodations for Students with Disabilities Regulation (REG02.20.01) .
Academic Integrity  Students are expected to conform to standards of academic integrity as described in the Code of Student Conduct, which can be found in the Code of Student Conduct. The student, by signing or writing their name on a homework assignment or test, affirms that they have neither given nor received unauthorized aid. (See "Homework Assignments" above for guidelines on acceptable collaboration on homework.)
NCSU Counseling center: The Counseling Center offers confidential counseling to NC State students experiencing personal, academic or vocational problems. Check out
Help for students in distress: Although the counseling center is a great help, sometimes it's hard to recognize when we need help. So we need to look out for each other too. Occasionally, you may come across a fellow student whose behavior worries you. You can and should report worrisome behavior to the NC State Cares website: You can report anonymously, but if you share your contact information, they can follow-up with you personally.