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Derek Egolf

Publications and source records attributed to Derek Egolf.

6 recordsLinked to original sources

Can LLMs Perform Synthesis?

How do LLMs compare with symbolic tools on program synthesis tasks? We investigate this question on several synthesis domains: LTL reactive synthesis, syntax-guided synthesis, distributed protocol synthesis, and recursive function synthesis. For each domain, we choose a state-of-the-art symbolic tool and compare it to an open-source, 32 billion parameter version of the Qwen LLM and the proprietary, frontier LLM GPT-5. We couple Qwen with a symbolic verifier and run it repeatedly until it either produces a solution that passes the verifier, or until there is a timeout, for each benchmark. We run GPT-5 once per benchmark and verify the generated output. In all domains, the symbolic tools solve more benchmarks than Qwen and either outperform or are about on par with GPT-5. In terms of execution time, the symbolic tools outperform GPT-5 in all domains, and either outperform or are very close to Qwen, despite the fact that the LLMs are run on significantly more powerful hardware.

cs.PL

Recursive Program Synthesis from Sketches and Mixed-Quantifier Properties

We present a novel approach for the synthesis of recursive programs from mixed-quantifier first-order logic properties. We solve this problem using a sketching-based, enumerative, counterexample-guided approach. Our algorithm learns syntactic constraints from counterexamples to prune the candidate space and employs a prophylactic pruning technique to avoid enumerating invalid candidates altogether. We implement our technique in a tool called Cataclyst and evaluate it on a suite of 60 benchmarks. We demonstrate that both counterexample generalization and prophylactic pruning significantly improve performance. Cataclyst solves 59/60 benchmarks, while variants of Cataclyst without counterexample generalization or prophylactic pruning solve fewer benchmarks. The only other tool that can handle mixed-quantifier specifications does not support sketching, so a direct comparison is not possible. This prior tool solves 12/60 benchmarks.

cs.LO

Accelerating Protocol Synthesis and Detecting Unrealizability with Interpretation Reduction

We present a novel counterexample-guided, sketch-based method for the synthesis of symbolic distributed protocols in TLA+. Our method's chief novelty lies in a new search space reduction technique called interpretation reduction, which allows to not only eliminate incorrect candidate protocols before they are sent to the verifier, but also to avoid enumerating redundant candidates in the first place. Further performance improvements are achieved by an advanced technique for exact generalization of counterexamples. Experiments on a set of established benchmarks show that our tool is almost always faster than the state of the art, often by orders of magnitude, and was also able to synthesize an entire TLA+ protocol "from scratch" in less than 3 minutes where the state of the art timed out after an hour. Our method is sound, complete, and guaranteed to terminate on unrealizable synthesis instances under common assumptions which hold in all our benchmarks.

cs.LO

Efficient Synthesis of Symbolic Distributed Protocols by Sketching

We present a novel and efficient method for synthesis of parameterized distributed protocols by sketching. Our method is both syntax-guided and counterexample-guided, and utilizes a fast equivalence reduction technique that enables efficient completion of protocol sketches, often significantly reducing the search space of candidate completions by several orders of magnitude. To our knowledge, our tool, Scythe, is the first synthesis tool for the widely used specification language TLA+. We evaluate Scythe on a diverse benchmark of distributed protocols, demonstrating the ability to synthesize a large scale distributed Raft-based dynamic reconfiguration protocol beyond the scale of what existing synthesis techniques can handle.

cs.LO

Synthesis of Distributed Protocols by Enumeration Modulo Isomorphisms

Synthesis of distributed protocols is a hard, often undecidable, problem. Completion techniques provide partial remedy by turning the problem into a search problem. However, the space of candidate completions is still massive. In this paper, we propose optimization techniques to reduce the size of the search space by a factorial factor by exploiting symmetries (isomorphisms) in functionally equivalent solutions. We present both a theoretical analysis of this optimization as well as empirical results that demonstrate its effectiveness in synthesizing both the Alternating Bit Protocol and Two Phase Commit. Our experiments show that the optimized tool achieves a speedup of approximately 2 to 10 times compared to its unoptimized counterpart.

cs.LO

Decoupled Fitness Criteria for Reactive Systems

The correctness problem for reactive systems has been thoroughly explored and is well understood. Meanwhile, the efficiency problem for reactive systems has not received the same attention. Indeed, one correct system may be less fit than another correct system and determining this manually is challenging and often done ad hoc. We (1) propose a novel and general framework which automatically assigns comparable fitness scores to reactive systems using interpretable parameters that are decoupled from the system being evaluated, (2) state the computational problem of evaluating this fitness score and reduce this problem to a matrix analysis problem, (3) discuss symbolic and numerical methods for solving this matrix analysis problem, and (4) illustrate our approach by evaluating the fitness of nine systems across three case studies, including the Alternating Bit Protocol and Two Phase Commit.

cs.LO