Logic programs are a powerful approach for solving NP-Hard problems. However, their declarative nature poses significant challenges in debugging. Unlike procedural paradigms, which allow for step-by-step inspection of program state, logic programs require reasoning about logical statements for fault localization. This complexity is especially significant in learning environments due to students' inexperience. We introduce FormHe, a novel tool that integrates logic-based techniques with Large Language Models (LLMs) to detect and correct issues in Answer Set Programming submissions. FormHe consists of two main components: a fault localization module and a program repair module. First, the fault localization module identifies specific faulty statements in need of modification. Next, FormHe applies program mutation techniques and leverages LLMs to repair the flawed code. The resulting repairs are then used to generate hints that guide students in correcting their programs. Our experiments with real buggy programs submitted by students show that FormHe accurately detects faults in 94% of cases and successfully repairs 58% of incorrect submissions.

Abstract In recent years, more people have seen their work depend on data manipulation tasks. However, many of these users do not have the background in programming required to write complex programs, particularly SQL queries. One way of helping these users is automatically synthesizing the SQL query given a small set of examples. Several program synthesizers for SQL have been recently proposed, but they do not leverage multicore architectures. This paper proposes Cubes, a parallel program synthesizer for the domain of SQL queries using input-output examples. Since input-output examples are an under-specification of the desired SQL query, sometimes, the synthesized query does not match the user’s intent. Cubes incorporates a new disambiguation procedure based on fuzzing techniques that interacts with the user and increases the confidence that the returned query matches the user intent. We perform an extensive evaluation on around 4000 SQL queries from different domains. Experimental results show that our parallel approach can scale up to 16 processes with super-linear speedups for many hard instances, and that our disambiguation approach is critical to achieving an accuracy of around 60%, significantly larger than other SQL synthesizers.