You can get points by either finding mistakes in the atom book or by solving problems.
Grades:3=2 points, 4=2.5 points, 5=3 points.
Deadline: June 30
Each mistake in the atom book (not counting solutions to exercises) gets you 0.1 points. Mark the mistakes on this page with your name, if it does not work you can use this google docs. Mistakes also include typos, bad grammar, and unclear parts (explain why), generally speaking anything that requires improvement. You don’t need to start to read the book from the beginning. The lecture corresponds to Chapters 3,4,7 and 10, but you are encouraged to find mistakes in other parts (later chapters have a higher expected mistake rate, so it might be profitable to look at them).
Each of the problems (see below) gets you 1 point if it is solved by ≥3 people including you, 2 points otherwise.
for some Find an example of oligomorphic atoms and a language over input alphabet which is recognised by a deterministic orbit-finite automaton, but is not recognised by any equivariant deterministic register automaton.
(b) there is some such that property can be defined by a formula of first-order logic which has shape
Define the regular expressions to be the smallest class of languages (over orbit-finite alphabets) which: contains all languages with finitely many words and is closed under orbit-finite union, concatenation and Kleene star . Do regular expressions define the same languages as nondeterministic-orbit finite automata?
The Lipa Summer School (click here for the page of the school, including registration) is a summer school on topics connected to logic in computer science. The school consists of 4 mini-courses given by:
My slides are now deemed a security risk. To run them in Chrome, click this button:
I promise I’m not trying to hurt your computer. Promise.
I will be working on a better solution.
These slides show how to decide equivalence of tree-to-string transducers using the Hilbert Basis Theorem. The idea is based on
Helmut Seidl, Sebastian Maneth, Gregor Kemper:
Equivalence of Deterministic Top-Down Tree-to-String Transducers is Decidable. FOCS 2015: 943-962
There are two parts:
The Lipa Summer School (click here for the page of the school, including registration) is a summer school on topics connected to logic in computer science. There will be 4 mini-courses given by:
I am leading an ERC Consolidator grant on automata and logic called “A unified theory of finite-state recognisability”. The main goal is to find algebraic structures (like monoids) for things like infinite trees or profinite words. However, I can be very flexible on the topic, as long as it is tangentially connected to logic or automata.
I am searching for talented postdocs and phd students. The deadline for applications is April 30, 2017. Send applications to me by email. Please feel to ask questions before that date!
Postdocs. The postdoc can begin at any time from June 1 until the end of 2017. The duration is 6 – 12 months, with a possibility of extension for another year. The application consists of your name and 1-2 names of people who can provide references. I am looking for people with a good track record in the top conferences of the field. Teaching is optional.
PhD students. A typical duration is 4 years, starting any time from June 1 until the end of 2017. In application please include a cv and 1-2 names of people who can provide references. I am looking for candidates with a strong background in mathematics.
Here is a way of drawing graphs of bounded tree width, inspired by metro maps. The horizontal black lines are graph edges, the coloured shapes are vertices, and the gray background is the tree underlying the decomposition.
The mathematical content of the picture is that a graph has tree width k if and only if it is a subgraph of a (k+1)-colourable chordal graph (thanks to Michał Pilipczuk for pointing this out).
In 2013, I joined the EATCS council. Here is what I promised to do:
I am a candidate for the EATCS council. My program consists of three items. The first item is something where I promise concrete action, the remaining two are more speculative.
Update. The first item is solved: starting with 2016, ICALP will be using the open access LIPICS system. As it turned out, this idea had overwhelming support inside the council.
A presentation on documents about Mojżesz Presburger from the archives of Warsaw University
The documents in high resolution: