Upcoming Deadlines and Events

Mon Feb 09
Guided problem set 3 due at 9pm
Tue Feb 10
Homework 3 due at 9pm

Recent Announcements

Thu Feb 05

Homework 2 solutions are available (along with with solutions for Lab 3a.)

Wed Feb 04

Homework 2 Problem 2 has been graded. As stated for Problem 1 in yesterday's announcements, a large number of submissions either did not include a (possibly empty) list of sources and collaborators; explain LLM usage; or have all group members declared within the Gradescope interface. You can fix all of these issues without penalty by submitting a regrade request by 9pm on Wed Feb 18.

Of course, you can also request a regrade for an actual grading error, but you must offer a brief written justification for why the grading was incorrect, and the final grade will still be based on what was actually submitted and not new info presented within the request itself.

Finally, we are unlikely to post announcements about individual homework grades from here on, so please check Gradescope regularly.

Tue Feb 03

  • Homework 3 asks you to prove several languages nonregular, and we believe the best way to do so is the use of fooling sets. Unfortunately, due to semester-by-semester schedule changes, fooling sets do not appear in the upcoming Guided problem set 3, and it is too late to change it. We recommend completing Zone 1 of Guided problem set 4 (still due Mon Feb 16) before attempting Homework 3. You'll also get to practice fooling set proofs (and reduction arguments) during lab on Wed Feb 4.

  • Grades have been released for Homework 1 Problem 1. Grading for Homework 1 Problem 2 is nearly complete (our typical goal is to have grades released within a week of submission for homework, but course staff pushed hard this time to have feedback available before Homework 2 was due.)

    Check your scores as soon as possible, and be mindful of the feedback left by the graders as you work on future assignments. You may submit regrade requests that include a brief written justification for why the problem was graded incorrectly until 9pm on Tue Feb 17.

    Two things stood out in particular for this homework:

    • A very large number of submissions either did not include a list of sources and collaborators or an explanation of how an LLM was used. Per course policy (which was repeated on the cover page for Homework 1), every part of every problem must include a list of collaborators and, when applicable, an explanation of LLM usage even if the list is empty (if the list is empty, you should write "Sources and collaborators: None" or similar; otherwise, we can only assume you forgot to cite your source.) Please remember there is no penalty for using outside sources including LLMs as long as you cite them and write your solutions in your own words. (Of course, if you rely on them too much, you won't get the experience of solving the problems, and that will be reflected in your exam performance.)

      Graders removed all points for problem parts that did not follow the above policy. However, you may submit regrade requests with your list of sources and LLM explanation to remove the penalties (if a penalty was applied in error, please point out where the sources are listed like you would when requesting a regrade for any other kind of grader error.) This opportunity to have the citation penalty removed will only be provided for the first three written homeworks.

    • You may not have received a score at all for Homework 1.1 if you're in a group and the assignment was submitted without listing all group members in Gradescope. If you're missing a score, please ask the submitting group member to add your name to the group (from Emily's end, this is done by pulling up the problem submission and clicking the "View or edit group" link under HW 1.1 in the upper right corner of the page.)

  • In case there's any confusion of where to look, all recent announcements will appear on the course website index page with older announcements available as well on the Announcements page. Some particularly timely announcements like the above (it should be useful for Homework 2) will be posted on Ed and Discord as well.

Thu Jan 29
  • Homework 1 solutions are available (along with with solutions for Lab 2a.)
  • Regular expression writing tips:
    • If you need to concatenate $n$ strings matching a regular expression $R$ where $n$ is a fixed non-negative integer, you can write it more concisely as $R^n$. For example, $(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})^3$ is equivalent to $(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})$.
    • Acceptable but not recommended: If you need to concatenate one or more strings matching a regular expression $R$, you might want to use the so-called "Kleene plus" notation $R^+$. For example, $(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})^+$ is equivalent to $(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})(\texttt{\color{BrickRed}0} + \texttt{\color{BrickRed}1}\texttt{\color{BrickRed}0})^*$. However, you need to be careful to distinguish between the superscript Kleene plus and a standard $+$ used for unions. As always, graders cannot and should not try to guess what you meant when it is unclear.
Mon Jan 26
  • As a reminder, Guided Problem Set 1 is due today Mon Jan 26 and Homework 1 is due tomorrow Tue Jan 27. We won't generally announce reminders about individual assignment deadlines, because they're listed at the top of the course web page.
  • In accordance with the already posted homework policies, the Homework 1 handout has been updated with a reminder to post the (possibly empty) list of sources and collaborators at the end of each lettered problem part.
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