State transformers and modes of computation

State transformers, which form the objects in a subequalizing category, are a generalization of the transition functions of automata. The 2-categorical properties of subequalizers are developed and related to adjunctions in a 2-category. A calculus of monads in a 2-category is presented, and general lifting theorems are proved. Applications to constructions in categorical automata theory are given, and a representation theorem for strong monads into the monad of continuations is proved.U of I OnlyETDs are only available to UIUC Users without author permissio