Labelled deduction is an approach to providing frameworks for presenting
and using different logics in a uniform and natural way by enriching the
language of a logic with additional information of a semantic
proof-theoretical nature.
Labelled deduction systems often possess attractive properties, such as
modularity in the way that families of related logics are presented,
parameterised proofs of metatheoretic properties, and ease of
mechanisability. It is thus not surprising that labelled deduction has
been applied to problems in computer science, AI, mathematical logic,
cognitive science, philosophy and computational linguistics - for
example, formalizing and reasoning about dynamic `state oriented'
properties such as knowledge, belief, time, space, and resources.