Second-Order Hyperproperties

Abstract We introduce Hyper 2 LTL, a temporal logic for the specification of hyperproperties that allows second-order quantification over sets traces. Unlike first-order logics hyperproperties, such as HyperLTL, LTL can express complex epistemic properties like common knowledge, Mazurkiewicz trace theory, and asynchronous hyperproperties. The model checking problem is, in general, undecidable. For expressive fragment where is restricted to smallest largest sets, we present an approximate model-checking algorithm computes increasingly precise under- overapproximations quantified based on fixpoint iteration automata learning. report encouraging experimental results with our algorithm, which implemented tool .