π€ AI Summary
This study addresses the formal characterization of an agentβs probabilistic epistemic state concerning specification satisfaction in program verification. To this end, the paper introduces a novel probabilistic epistemic dynamic logic, termed PEDAL, which precisely models epistemic dynamics by endowing the set of program valuations in propositional dynamic logic (PDL) models with a probability measure. The main contributions include the first integration of probability measures into dynamic epistemic logic, the construction of a Hilbert-style axiomatization featuring infinitary inference rules, and strategies to mitigate the resulting proof-theoretic complexity. Furthermore, the work establishes a formal semantics and a corresponding axiomatic system for PEDAL and proves its soundness and strong completeness.
π Abstract
I introduce PEDAL -- a probabilistic epistemic logic meant to capture, in propositional dynamic terms, the epistemic state of an agent engaged in checking whether a program meets its specification. Semantically, PEDAL is built `on top of' PDL and uses probability measures defined on the set of possible program valuations of an otherwise-specified PDL-model. A Hilbert system with one infinitary rule is provided and proved to be sound and complete. Near the end, I discuss possible ways to circumvent infinitary proof difficulties.