CHC-COMP-21 is the fourth competition of solvers for Constrained Horn Clauses. In this year, 7 solvers participated at the competition, and were evaluated in 7 separate tracks on problems in linear integer arithmetic, linear real arithmetic, arrays, and algebraic data-types. The competition was run in March 2021 using the StarExec computing cluster. This report gives an overview of the competition design, explains the organisation of the competition, and presents the competition results.

翻译：CHC-COMP-21是受约束的非洲之角条款的第四次解决者竞赛。 今年,有7个解决者参加了这次竞赛,并以7个不同轨道对线性整数计算、线性实际算术、数组和代数数据类型等问题进行了评估。 2021年3月,使用StarExec计算组进行了竞争。本报告概述了竞争设计,解释了竞争的组织结构,并介绍了竞争结果。