A Modular ASPIC+ Argumentation System (pickaxe)

Abstract

We present pickaxe-rs, an open-source implementation of the ASPIC+ framework for structured argumentation (Modgil & Prakken, 2013; 2014), extended with the accrual semantics of Prakken (2019). The system provides a modular pipeline — grounding, argument construction, attack computation, and evaluation — supporting eight Dung-style semantics with multiple solver backends, including a propositional SAT encoding with optional SCC decomposition for scalable evaluation of large frameworks. The language is restricted to the Bernays–Schönfinkel fragment of first-order logic, ensuring that Herbrand grounding always terminates over finite domains. Argument preference is handled through last-link and weakest-link orderings with elitist and democratic lifting strategies. We validate the implementation through a systematic verification programme comprising randomly generated argumentation frameworks, paradigmatic examples drawn from the literature, and adversarial test cases constructed from known bugs in existing solvers.