🤖 AI Summary
This paper addresses the series-parallel pomset recognition problem in concurrent program modeling. To overcome the high query cost and inefficient counterexample handling of conventional approaches—especially on complex, long-structured pomsets—we propose an active learning framework for pomset recognizers. Our contributions are threefold: (1) an exponentially more efficient counterexample analysis algorithm; (2) a refined $L^lambda$ algorithm that suppresses redundant membership queries and equivalent queries; and (3) an extended $W$-method to generate a finite, complete test suite, ensuring reliable equivalence checking. Integrating the Minimally Adequate Teacher (MAT) paradigm, algebraic language recognition, and pomset theory, our framework significantly reduces both query complexity and counterexample processing overhead. In the theoretically optimal case, it achieves exponential speedup, thereby enhancing both the efficiency and practicality of automated pomset inference.
📝 Abstract
Pomsets are a promising formalism for concurrent programs based on partially ordered sets. Among this class, series-parallel pomsets admit a convenient linear representation and can be recognized by simple algebraic structures known as pomset recognizers. Active learning consists in inferring a formal model of a recognizable language by asking membership and equivalence queries to a minimally adequate teacher (MAT). We improve existing learning algorithms for pomset recognizers by 1. introducing a new counter-example analysis procedure that is in the best case scenario exponentially more efficient than existing methods 2. adapting the state-of-the-art $L^{lambda}$ algorithm to minimize the impact of exceedingly verbose counter-examples and remove redundant queries 3. designing a suitable finite test suite that ensures general equivalence between two pomset recognizers by extending the well-known W-method.