Inclusão versus Recuperação em Bases de Crenças


When contracting a formula from a belief base, two desiderata compete: one
wants to avoid including any new belief in the process (inclusion) but may
want to be able to recover information that was in the base before the
contraction took place (recovery).

The AGM paradigm imposes both constraints on contraction operations. However,
for finite belief bases inclusion and recovery cannot be simultaneously
satisfied.

In this work, we examine constructions that weaken the inclusion constraint
and retain some form of recovery. We show that depending on what is allowed to
be added, we obtain a counterpart to the principle of minimal change, where we
add just enough information to allow recovery.