Deontic logic is the field of philosophical
logic that is concerned with
obligation,
permission, and related concepts. Alternatively, a deontic logic is a formal system that attempts to capture the essential logical features of these concepts. Typically, a deontic logic uses
OA to mean
it is obligatory that A, (or
it ought to be (the case) that A), and
PA to mean
it is permitted (or permissible) that A. The term
deontic is derived from the
ancient Greek déon - δέον (gen.:
δέοντος), meaning, roughly,
that which is binding or proper.