CS 2800 is a 4-credit course. The Office of the Registrar has useful information.

Sections

• 1: Manolios, M,W,Th 9:15AM-10:20AM, WVG 104 on Bluejeans.
• 2: Shivers, M,W,Th 10:30PM-11:35PM, Robinson 409
• 3: Shivers, M,W,Th 1:35PM-2:40PM, WVH 108

For Instructors, TAs, and Tutors, click on Contact Info on your left.

You are required to check for announcements daily.

Rules

• If you don't understand something, please ask questions. We love questions. One of the benefits of attending a university as opposed to reading a book is that you get to interact with faculty.
• Give us feedback. Tell us what works; what doesn't. Tell us what you like about the class and what you don't like.
• In class, stay engaged during the lectures. There are only three hours of lectures a week and we want your undivided attention. Therefore, the use of electronic devices (computers, recording devices, phones, etc) is not allowed, without permission. The only exception is when we takes quizzes using PollEverywhere, which will require that you have a cell phone or laptop. Bring that with you every day.
• We will be fair with everyone, so rest assured that all the students will play by the same rules. To that end, we have clear policies. Make sure you understand them, as they apply to everyone in the class. For example, late homeworks will not be accepted under any circumstances. If you ask us to make an exception for just you, the answer will be no. If you ask us to change the due date for everyone, then we will consider it. Please feel free to question the policies; if you suggest improvements, we can change our policies (and have done so in the past).

Books and Supplies

There is no required book. If you want a reference that also includes a lot of exercises, then consider: Computer Aided Reasoning. Kaufmann, Manolios, Moore. You can order it from here. Please note that the book was written for at least upper level undergraduate students, so expect parts of the book to be hard. Also, in class we use a version of ACL2 that includes contracts and lots of other things that are not mentioned in the book. Nevertheless, this is the standard reference for ACL2 and contains many exercises whose solutions are available online.

Software

We will be using the ACL2s system. Please download it and install it on your machines. It is also available on the Khoury Virtual Desktops, which allow you to run ACL2s with only a browser. See lab 1 for more information.

Academic Integrity

Read and intimately familiarize yourselves with the Northeastern Academic Integrity policy.

Please read and sign the Course Contract.

Warning: We do not tolerate any violations. If we believe that you violated the policy, we will report you to the university and to the college. If you remain in the class, your grade will be reduced, perhaps to an F, at our discretion. In addition the university and the college can impose further penalties, including not allowing you to go on co-op; even expulsion from the university is possible in severe cases.

For example, here is something you cannot do, but again, read the full policy, the course contract and see Mitch Wand's Web page on the topic.

Unauthorized Collaboration: The University defines unauthorized collaboration as instances when students submit individual academic works that are substantially similar to one another. While several students may have the same source material, the analysis, interpretation, and reporting of the data must be each individual's independent work.

You can only collaborate with your partners on homework problems. Besides staff, the use of any other sources for homework solutions is a violation of the academic integrity policy.

For quizzes, the electronic device you use can only have the polleverywhere app/webpage open during quizzes. The use of lecture notes, ACL2s, or any other applications during quizzes is a violation of the academic integrity policy. Sharing information with other students, taking quizzes for other students or communicating with other students is also a violation of our academic integrity policy.

Exams

There are exactly two exams. They will take place at the following times:

• Thursday, Feb 20, 6-8pm
Manolios Section: Hayden 322
All Shivers Sections: Hurtig 130
• Monday, April 6, 6-8pm

Let us know by January 15 if you have a conflict.

Grading

Grades will be determined as follows.

• Homeworks: 20%
• Exam 1: 30%
• Exam 2: 30%
• Quizzes: 20%

There are only 2 exams and there is no final.

Quizzes will occur regularly. Be prepared for a short quiz every day. Only a subset of the quizzes might be graded. If you are not present for a quiz or if you do not have Poll Everywhere working, you will get 0 points. We will drop the lowest 10% of quizzes.

Homeworks will be given about once a week. Your homework grade will be based on your top ten homeworks. You will mostly work in groups. We will give you instructions on group sizes and composition. We recommend that you to first try to solve the problems on your own. Then meet with your partners to go over your solutions and solve any unresolved problems. We may only grade a subset of the problems assigned. Homeworks will be due on Monday at 10:00PM, unless otherwise noted.

You will spend most of your time in labs working on problems that we distribute in advance. If you solve the problems on your own before lab and are confident in your solutions, there is no need to show up. If you did not have time to solve the problems, or you tried and ran into trouble, then go to lab.

PollEverywhere Instructions

Sign up on the website using your Husky email account here.

In class, we will periodically ask you to respond to a poll. We will either provide a link to the poll or give you our PollEverywhere user name. To join any active poll, either click the provided link--or, if we give you our user name, you can click "Join a Presentation" when logged into PollEverywhere on your laptop or phone (if you install the PollEverywhere app).

If you use the app, log into PollEverywhere using your Husky email.

Grading Notes

• You can take 1 double-sided sheet of paper to each exam.
• You have exactly 1 week after any assignment, quiz, or exam is graded to challenge your grade. After that, we will not change your grade.
• You are responsible for making sure that we entered the right points on Blackboard. If you notice any data entry errors, please inform us right away.
• You must take all exams and quizzes in the section you are registered for. If you take an exam or a quiz in a different section that the one you are registered for, you will not get any points for that exam or quiz.

Prerequisites

CS 1800 and CS 2500.
If you do not have this background you should get the permission of the instructor. Our policy is that we do not grant exemptions if you did not getting passing grades in both the prerequisites: experience has shown that this is the best policy for students.

Schedule

Week	Topics	Readings
Jan 6 L1-L3	Introductions & motivation, slides Syllabus, class webpage, programming review, slides Designing data-driven programs, the ACL2s development environment, slides, code	None None None
Jan 13 L4-L6	Basic data types, expressions, syntax & semantics of atomic data and associated primitive functions, slides Syntax & semantics of lists, design considerations of the ACL2s core language, contracts, termination, slides, code helpful function, quote, let, Datatypes: enumerated, range, product, record, union, list, (mutually) recursive, design recipe slides, code	2.1-2.4 2.5-2.10 2.11-2.13
Jan 20 L7-L8	Property-based testing, test?, thm, program mode and defunc settings, slides, code Property-based testing in industry, Fuzzing, security applications, slides, code	2.14-2.17 None
Jan 27 L9-L11	Boolean logic, truth tables, characterization of formulas, Security: one-time pads, slides Introduction to P=NP, Properties of Boolean operators, Proof methods: instantiation, case analysis, equational proofs, decision procedures, slides Boolean logic in ACL2s, Normal forms, Set Theory connections, applications, slides	3-3.2 3.3-3.5 3.6-3.10
Feb 3 L12-L14	Limitations of Boolean logic, intro to equational reasoning for programs, slides Axioms for equality, cons-first-rest axioms, definitional axioms, instantiation, contract checking and completion, slides On the computational nature of conjectures, using ACL2s to understand conjectures and counterexamples, equational reasoning with nested Boolean operators, slides	4 4.1 4.2-4.4
Feb 10 L15-L17	Undecidability results, Reasoning about arithmetic, program equivalence: proving correctness of an exponential-time improvement, slides, code Context vs. theorems, derived context, numeric reasoning in C & other languages, slides, C code How to prove theorems using equational reasoning, formalization examples, proof examples, slides, formalization files, C formalization code	4.5 4.6 None
Feb 17 L18-L19	Definitions: soundness, termination, contracts, the ACL2s Definitional Principle Termination, measure functions, Review	5.1 None
Feb 24 L20-L22	Using termination to show soundness of common recursions schemes, big-Oh analysis as a refinement of termination Undecidability of halting problem Proof by contradiction, mathematical induction, well-foundnesses, a proof that mathematical induction works, how to extract induction schemes from admissible recursive functions	5.2-5.3 5.4-5.5 6-6.2
Mar 9 L23-L25	Using induction to prove program correctness Data-function-induction trinity, Importance of termination Induction like a professional, reasoning about algorithms: sorting, correctness	6.3 6.4-6.6 6.7
Mar 16 L26-L28	Classes cancelled due to coronavirus move out Generalization, lemma generation, dealing with induction failure Intro to reasoning about accumulators	None 6.8 6.9
Mar 23 L29-L31	Tail recursion: efficiency considerations, how to prove correctness Accumulator reasoning examples Abstract and algebraic data types	6.9 6.9 8.1-8.2
Mar 30 L32-L34	Observational equivalence Reasoning about imperative programs: defining the semantics of a simple while language in ACL2s Reasoning about imperative programs using loop invariants; checking such proofs in ACL2s	8.3-8.4 9-9.2 9.3
Apr 6 L35-L37	Reasoning about imperative programs and security, exam2 review Compiler correctness Mathematical logic: syntax, semantics, proof theory, undecidability, incompleteness, slides
Apr 13 L38	A look back: Logic and the birth of computer science; A look forward: what's next	None