Belief contraction and erasure in fragments of propositional logic

Abstract Recently, belief change within the framework of fragments propositional logic has gained attention. In context revision, it been proposed to refine existing operators so that they operate and result revision remains in fragment under consideration. Later, this notion refinement was generalized operators. Whereas allowed one define concrete rational adapted update, be specified for contraction erasure. We propose a specific erasure operators, called reasonable refinement. This allows us provide refined satisfy basic postulates. study logical properties two model-based Our approach is not limited Horn but applicable many logic, like Krom affine fragments.