SAS 2022
Mon 5 - Wed 7 December 2022 Auckland, New Zealand
co-located with SPLASH 2022
Tue 6 Dec 2022 16:30 - 17:00 at AMRF Auditorium - Invariant and Program Synthesis Chair(s): Subhajit Roy

Automatically generating invariants, key to computer-aided analysis of probabilistic and deterministic programs and compiler optimisation, is a challenging open problem. Whilst the problem is in general undecidable, the goal is settled for restricted classes of loops. For the class of solvable loops, introduced by Kapur and Rodríguez-Carbonell in 2004, one can automatically compute invariants from closed-form solutions of recurrence equations that model the loop behaviour. In this paper we establish a technique for invariant synthesis for loops that are not solvable, termed unsolvable loops. Our approach automatically partitions the program variables and identifies the so-called defective variables that characterise unsolvability. We further present a novel technique that automatically synthesises polynomials, in the defective variables, that admit closed-form solutions and thus lead to polynomial loop invariants. Our implementation and experiments demonstrate both the feasibility and applicability of our approach to both deterministic and probabilistic programs.

Tue 6 Dec

Displayed time zone: Auckland, Wellington change

15:30 - 17:00
Invariant and Program SynthesisSAS at AMRF Auditorium
Chair(s): Subhajit Roy IIT Kanpur
15:30
30m
Talk
Bootstrapping Library-Based Synthesis
SAS
Kangjing Huang Purdue University, USA, Xiaokang Qiu Purdue University, USA
16:00
30m
Talk
Automated Synthesis of Asynchronizations
SAS
Sidi Mohamed Beillahi University of Toronto, Ahmed Bouajjani IRIF, Université Paris Diderot, Constantin Enea Ecole Polytechnique / LIX / CNRS, Shuvendu K. Lahiri Microsoft Research
16:30
30m
Talk
Solving Invariant Generation for Unsolvable Loops
SAS