Eldarica

Eldarica is a model checker for Horn clauses, Numerical Transition Systems, and software programs. Inputs can be read in a variety of formats, including SMT-LIB 2 and Prolog for Horn clauses, and fragments of Scala and C for software programs, and are analysed using a variant of the Counterexample-Guided Abstraction Refinement (CEGAR) method. Eldarica is fast and includes sophisticated interpolation-based techniques for synthesising new predicates for CEGAR, enabling it to solve a wide range of verification problems.

The Eldarica C parser accepts programs augmented with various primitives from the timed automata world: supporting concurrency, clocks, communication channels, as well as analysis of systems with an unbounded number of processes (parameterised analysis).

There is also a variant of Eldarica for analysing Petri nets: http://www.philipp.ruemmer.org/eldarica-p.shtml

Eldarica has been developed by Hossein Hojjat and Philipp Ruemmer, with further contributions by Zafer Esen, Filip Konecny, and Pavle Subotic.

There is a simple web interface to experiment with the C interface of Eldarica: https://eldarica.org/eldarica

Documentation

You can either download a binary release of Eldarica, or compile the Scala code yourself. Since Eldarica uses sbt, compilation is quite simple: you just need sbt installed on your machine, and then type sbt assembly to download the compiler, all required libraries, and produce a binary of Eldarica.

After compilation (or downloading a binary release), calling Eldarica is normally as easy as saying

./eld regression-tests/horn-smt-lib/rate_limiter.c.nts.smt2

When using a binary release, one can instead also call

java -jar target/scala-2.*/Eldarica-assembly*.jar regression-tests/horn-smt-lib/rate_limiter.c.nts.smt2

A set of examples is provided on https://eldarica.org/eldarica, and included in the distributions directory regression-tests.

You can use the script eld-client instead of eld in order to run Eldarica in a server-client mode, which significantly speeds up processing of multiple problems.

A full list of options can be obtained by calling ./eld -h.

The options -disj, -abstract, -stac can be used to control predicate generation. For the option -stac to work, it is currently necessary to have Yices (version 1) installed, as this is a dependency of the Flata library.

The option -sym can be used to switch to the symbolic execution engine of Eldarica, which will then be applied instead of CEGAR.

Papers

• The canonical Eldarica reference: "The Eldarica Horn Solver" http://uu.diva-portal.org/smash/get/diva2:1268767/FULLTEXT01.pdf
• An older tool paper covering, among others, Eldarica: "A Verification Toolkit for Numerical Transition Systems - Tool Paper." http://link.springer.com/chapter/10.1007%2F978-3-642-32759-9_21
• "Guiding Craig Interpolation with Domain-specific Abstractions" http://link.springer.com/article/10.1007%2Fs00236-015-0236-z
• "Accelerating Interpolants" http://link.springer.com/chapter/10.1007%2F978-3-642-33386-6_16
• "Disjunctive Interpolants for Horn-Clause Verification" http://link.springer.com/chapter/10.1007%2F978-3-642-39799-8_24
• "Exploring interpolants" http://dx.doi.org/10.1109/FMCAD.2013.6679393

Related Links

• A library of Horn clause benchmarks: https://github.com/sosy-lab/sv-benchmarks/tree/master/clauses
• Numerical transition system benchmarks: http://nts.imag.fr/index.php/Main_Page