The aim of this paper is to extend the system of belief revision developed by Alchourrón,
Gärdenfors and Makinson (AGM) to a more general framework. This extension enables a
treatment of revision not only by single sentences but also by any sets of sentences,
especially by infinite sets. The extended revision and contraction operators will be called
general ones, respectively. A group of postulates for each operator is provided in such a way
that it coincides with AGM's in the limit case. A notion of the nice-ordering partition is …

The aim of this paper is to extend the system of belief revision developed by Alchourr on, G
ardenfors and Makinson (AGM) to a more general framework. This extension not only
enables a treatment of revision by single sentences but also by any sets of sentences,
especially by in nite sets. The extended revision and contraction operators will be called
general ones, respectively. A group of postulates for each operator is provided in such a way
that it coincides with AGM's in the limit case. A notion of the nice-ordering partition is …