Posts

I am co-organising two workshops in July 2023: WORReLL'23 (see here) and Autobóz 2023 (see here). WORReLL'23 WORRELL'23 is a one-day satellite workshop at ICALP'23. The aim of the workshop is to bring together researchers from the community and showcase cutting-edge research on Reachability, Recurrences, and Loops.

Marcel Moosbrugger presented our joint work (see here) on invariant generation for unsolvable loops at the ACM SIGPLAN 29th Static Analysis Symposium (SAS 2022). Abstract Automatically generating invariants, key to computer-aided analysis of probabilistic and deterministic programs and compiler optimisation, is a challenging open problem.

James (Ben) Worrell gave a keynote talk on algorithmic analysis of dynamical systems at the 48th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2021). During his talk, Ben presented some of our ongoing work on inequality decision problems for low-order holonomic sequences (see here).

Slides on minimality and positivity for second-order holonomic sequences. Variations given at Mathematical Foundations of Computer Science 2021 (MFCS, Tallinn), the joint Forsyte (TU Wien) and Institute of Science & Technology Seminar, and the Open University Dynamical Systems Seminar.

Joël Ouaknine gave an invited talk on holonomic techniques, periods, and decision problems at Foundations of Software Technology and Theoretical Computer Science conference (FSTTCS 2020). During his talk Joël presented some of our ongoing work on inequality decision problems for low-order holonomic sequences (see here).

In his book, The Design of Everyday Things, Norman argues that a skilled practitioner or expert minimises the cognitive burden of performing tasks by automating subroutines and processes. Thus the expert need only engage consciously with the minutiae and subtleties of the task at hand.

The Markov Reachability Problem We are interested in decision problems for Markov chains and in particular, the Markov Reachability Problem. Given a stochastic matrix $K\in\mathbb{Q}^{d\times d}$ and positive $r\in\mathbb{Q}$, determine whether there exist an $n\in\mathbb{N}$ such that $K^n(1,2)=r$.