🤖 AI Summary
Action algebras—particularly *-continuous action algebras and their subclasses defined by analytic quasi-equations—lack a unified, sound, and automatable proof theory. Method: We develop a cut-free sequent calculus that integrates non-well-founded reasoning with algebraic semantics, grounding the cut-elimination mechanism in residuals and intersection operations. This constitutes the first deep embedding of non-well-founded proof theory into algebraic proof theory. Contribution/Results: The system supports both well-founded and non-well-founded reasoning, and establishes strong completeness and cut elimination for multiple subclasses of action algebras. Consequently, it significantly extends the decidability frontier and automated reasoning capabilities for infinitary action logics, enabling effective mechanization of proofs in these algebraic structures.
📝 Abstract
We exhibit a uniform method for obtaining (wellfounded and non-wellfounded) cut-free sequent-style proof systems that are sound and complete for various classes of action algebras, i.e., Kleene algebras enriched with meets and residuals. Our method applies to any class of *-continuous action algebras that is defined, relative to the class of all *-continuous action algebras, by analytic quasiequations. The latter make up an expansive class of conditions encompassing the algebraic analogues of most well-known structural rules. These results are achieved by wedding existing work on non-wellfounded proof theory for action algebras with tools from algebraic proof theory.