Stephen Checkoway

@stevecheckoway.bsky.social

Associate Professor of Computer Science at Oberlin College. No kings, no nazis, no war.

You could absolutely go to him "They can tear down your ballroom, You'll never finish your arch. They can take your name off everything, But the one legacy that nobody could ever undo or change or take away from you would be if you added a state. That extra star on the flag would be TRUMP'S STAR."

I'm using a new-to-me book for teaching theory of computation this semester. For some reason, the author never draws a PDA nor a Turing machine! In the introduction to TMs, here's the first example for the language A = {a^n b^n c^n | n ≥ 0}. Contrast with my implementation.

A table showing the transition function delta for the language. This textbook uses the turnstile character ⊢ to mark the start of the tape. This TM uses ⊣ to mark the right hand end of the tape after encountering the first blank and then scans back and forth between the to marks, blanking out one a, one b, and one c each time.Photo of a whiteboard showing a TM for the same language, this time as a transition diagram rather than just a collection of transitions.

I didn't use the initial turnstile symbol (⊢). Accounting for it would just involve a new start state that just moves right over the ⊢. My algorithm is also slightly different. It scans right, marking off one a, one b, and one c in order. Once it reaches the first c, it scans back to the left until it finds the first marked off a (an x character on the tape) and then moves right and repeats. Once all the as have been marked, it checks that all bs and all cs have been marked by scanning to the right until it finds the first blank symbol. Then it accepts.My TM in JFLAP showing that it accepts some strings in the language and rejects some strings not in the language.

I had a meeting this morning in the Science Center which is a building across campus from me. When I left an hour ago, this was on the TV in the main hallway. I have no idea what this is for. And weirdly, it’s still up an hour later! (I left a thermos in the conference room and just retrieved it.)

Congrats to
Stephen Checkoway
associate Professor of Computer Science

I just received a bizarre anti-Sherrod Brown text ad that claims he's pro-Trump. Text: Sherrod Brown: Pro-Trump and WRONG for Ohio Brown ADMITTED he supports Trump's tariffs. He SUPPORTS & ENABLES Trump. He BACKS his ANTI-WORKER Agenda. And OPPOSES Medicare For All. Vote NO on Sherrod Brown.

Sherrod Brown
Pro-Trump.
Wrong for Ohio.
Newspaper  quotes:
"Brown supports Trump's Tariffs" 3/9/18
"Sen. Brown Applauds Trump's Executive Action" 1/24/17
Paid for by Enough Promises Ohio and not authorized by any candidate or candidate's committee

and his people ... studying very dilapidated golf course. ... AL: "Burgum and people" -- that refers to you? GW: don't know. AL: you see others? you said someone identified on left who was part of President's staff. who was it? GW: natalie harp. AL: post says work will begin 9/1 GW: yes. /75

I'm a pretty big AI skeptic but I did have a pretty amusing thing happen last night. I fed the robot a PDF containing a proof I wrote that the intersection of a context-free language and a regular language is context-free. I asked it to give me a lean proof. It restated my proof, concisely.

This morning I re-watched my video argument with the NY Times' Patrick Healy, and it's clear that the Times believes if it says explicity that the Trump regime is assaulting democracy, that would undermine its work to investigate how the regime is assaulting democracy. What an absurd position.

Mark Jacob@markjacob.bsky.social · 4w ago

🧵🧵🧵 The NY Times posted a 15-minute video today in which I got to tell NYT what’s wrong with its coverage. They said they saw my critical posts on Bluesky and invited me to do a video with them to air my grievances. Weird, right? I didn’t hold back. I blasted their sanewashing of MAGA extremism.