On Angels and Demons: Strategic (De)Construction of Dynamic Models

Abstract: In recent years, there has been growing interest in logics that formalise strategic reasoning about agents capable of modifying the structure of a given model. This line of research has been motivated by applications where a modelled system evolves over time, such as communication networks, security protocols, and multi-agent planning. In this paper, we introduce three logics for reasoning about strategies that modify the topology of weighted graphs. In Strategic Deconstruction Logic, a destructive agent (the demon) removes edges up to a certain cost. In Strategic Construction Logic, a constructive agent (the angel) adds edges within a cost bound. Finally, Strategic Update Logic combines both agents, who may cooperate or compete. We study the expressive power of these logics and the complexity of their model checking problems.