Published: 13th September 2021
DOI: 10.4204/EPTCS.344
ISSN: 2075-2180


Proceedings 8th Workshop on
Horn Clauses for Verification and Synthesis
Virtual, 28th March 2021

Edited by: Hossein Hojjat and Bishoksan Kafle

An Overview of the HFL Model Checking Project
Naoki Kobayashi
Termination Analysis of Programs with Multiphase Control-Flow
Jesús J. Domenech and Samir Genaim
Regular Path Clauses and Their Application in Solving Loops
Bishoksan Kafle, John P. Gallagher, Manuel V. Hermenegildo, Maximiliano Klemen, Pedro López-García and José F. Morales
Reducing Higher-order Recursion Scheme Equivalence to Coinductive Higher-order Constrained Horn Clauses
Jerome Jochems
A Fixed-point Theorem for Horn Formula Equations
Stefan Hetzl and Johannes Kloibhofer
Knowledge-Assisted Reasoning of Model-Augmented System Requirements with Event Calculus and Goal-Directed Answer Set Programming
Brendan Hall, Sarat Chandra Varanasi, Jan Fiedor, Joaquín Arias, Kinjal Basu, Fang Li, Devesh Bhatt, Kevin Driscoll, Elmer Salazar and Gopal Gupta
Competition Report: CHC-COMP-21
Grigory Fedyukovich and Philipp Rümmer


This volume contains revised and extended versions of papers and invited talks presented at the 8th workshop on Horn Clauses for Verification and Synthesis (HCVS), which took place virtually on 28 March, 2021 due to COVID-19 pandemic as an affiliated workshop of ETAPS. The aim of the HCVS workshop series is to stimulate and promote international research and collaboration by bringing together the CLP and CAV communities on efficiently solving program verification and synthesis problems presented as constrained Horn clauses (CHCs). The included papers illustrate CHCs as a common representation for specifying and verifying program properties and also for implementing practical tools based on this.

We would like to thank the editorial office of EPTCS, in particular editor-in-chief Rob van Glabbeek for his help and support in hosting this event. Our sincere thanks to the program committee and steering committee members (especially Fabio Fioravanti) of HCVS, and local organizers of ETAPS and to the reviewers of the papers for their support and hard work.

Volume Editors

Hossein Hojjat, Tehran Institute for Advanced Studies, Iran
Bishoksan Kafle, IMDEA Software Institute, Spain

August 2021