## Notices

#### Posted by Paul Hunter Thursday 19 May 2022, 12:13:44 AM.

Hi all,

This should (hopefully) be the final message from me for this course. Thank you all for seeing it through to the end, it is always pleasing when the number of exam submissions matches the number of Assignment 1 submissions. I was very impressed with this year's cohort - based on your assignments and exam submissions I would say that you are the strongest group I have seen take this course. Quite a few of you have shown a real aptitude for this subject, and I hope that many of you continue to explore Theoretical CS.

A big shout out to Ethan and Ian - I sat in on a couple of their tutorials, so I know firsthand how much they added to the course.

Your assignment marks should now be visible on the course website. The marks shown include lateness penalties/early bonuses - i.e. the marks are what was submitted. If there are any gross inaccuracies, please let me know - marks can be amended with not too much trouble. I am happy to provide feedback on any mark (including exam marks when they become available), please drop me an email if you have any questions.

The forum will remain open for a couple of weeks - and the exam is now (effectively) public domain, so feel free to discuss questions/solutions.

I'd like to finish with my favourite proof from your exams - the student shall remain anonymous (primarily because I'm not sure I can find which paper it came from). Here is (my paraphrasing of) their beautiful proof of Q2(a):

L is regular, so rev(L) is regular (from Assignment 1).
Regular languages are closed under concatenation so L' = L·rev(L) is regular. [many of you got here]
The language P of all palindromes is context-free (from lectures).
Because the intersection of a CFL and a regular language is context-free, we therefore get that mirror(L) = P∩L' is context-free.

Thank you all again,

Paul

#### Posted by Paul Hunter Monday 09 May 2022, 08:47:16 AM.

Hi all,

The final exam is now available on the course website (under Activities).

It is due at 9am (Sydney time) on Tuesday 10 May 2022 .

Multiple submissions are acceptable - please remember to submit early and submit often.

I will be around for questions on ed from 9-11 today; any significant announcements will be made through course-wide announcements - so please keep an eye on your email.

Paul

#### Posted by Paul Hunter Friday 22 April 2022, 12:45:30 AM.

Hi all,

As mentioned in today's lecture, there will be a [recorded] Q&A session on Monday (2pm-4pm), where I will answer any questions you have about the course, and work through solutions to several problems (e.g. previous exam questions) - ideally suggested by you. This lecture is completely optional, but will offer the most benefit with student participation.

It has occurred to me that the consultation scheduled for next week is not well timed for anyone with Assignment 4 questions. So the Q&A session on Monday will also be open for questions/discussions about the ongoing assignment - though, like the consultations, this is intended to be somewhat interactive and student driven.

Paul

#### Upcoming Due Dates

There is nothing due!