In cross-level plans, some of the actions are in fact steps of making later parts of the plan. Trying to formalize such plans using modal logic ran into familiar but serious problems. Representing beliefs as abstract objects is a standard alternative, but there is then no semantics to explain the interaction of knowledge and action.

The goal of this paper is to present a reasoning system, called METAFOL, embodying the features of a self-reflective system, i.e. a system which has a representation of its own code and is able to reason about and, possibly, extend or modify it. These features have been achieved by employing a logical meta-theory, which represents the computation implementing deduction in its object theory. Computation is represented in the meta-theory as logical manipulation of a set of terms, called logic tactics. They are the logical counterpart of a set of programs, called program tactics, implementing deduction in the object theory. The mapping existing between logic tactics and program tactics allows us to synthesize correct programs by reasoning in the meta-theory. It also allows us to implement a reflection mechanism which can be exploited to execute logic tactics and/or compile them into the system code as program tactics. Keywords: Self-reflective systems; Metatheoretic reasoning; Proof chec...

An agent who executes plans in which some steps are the making of the very plan he is executing must somehow connect the plans that he executes with the plans that he reasons about.