Formalizing perspectival defeasible reasoning

I provide a unique formalism for defeasible reasoning that takes into account how an agent activates a perspective in response to a situation in which reasoning using a concept is called for, how each perspective is organized, and how the contents of each activated perspective is related to the contents of other perspectives. I name the proposed structure a perspectival defeasible theory. To formalize the theory, I present graphical representations of the theory motivated by a psychologically plausible cognitive theory, then I present a proof theory