Input/output logics

In a range of contexts, one comes across processes
resembling
inference, but where input propositions are not in
general included among outputs,
and the operation is not in any way reversible. Exa
mples arise in contexts of
conditional obligations, goals, ideals, preferences
, actions, and beliefs. Our purpose is
to develop a theory of such input/output operations
. Four are singled out: simple-
minded, basic (making intelligent use of disjunctiv
e inputs), simple-minded reusable
(in which outputs may be recycled as inputs), and b
asic reusable. They are defined
semantically and characterised by derivation rules,
as well as in terms of relabeling
procedures and modal operators. Their behaviour is
studied on both semantic and
syntactic levels