Abstract
Classical axiomatizations of belief revision include
a postulate stating that if new information is consistent with initial beliefs, then revision amounts to
simply adding the new information to the original
knowledge base. This postulate assumes a conservative attitude towards initial beliefs, in the sense
that an agent faced with the need to revise them will
seek to preserve initial beliefs as much as possible.
In this work we look at operators that can assume
different attitudes towards original beliefs. We provide axiomatizations of these operators by varying
the aforementioned postulate and obtain representation results that characterize the new types of operators using preorders on possible worlds. We also
present concrete examples for each new type of operator, adapting notions from decision theory