Proofs as Reasons, a semantical approach to LP

A well-known problem with formal logics of knowledge is "logical 
omniscience," one knows too much.  This breaks down into two 
subproblems: one knows all tautologies, and one's knowledge is closed 
under consequence.  A way of addressing the second of these is to move 
from knowledge simpliciter, to knowledge for a reason.  Then, as 
consequences become 'further away' from one's original knowledge, 
reasons for them become more complex, thus providing a kind of resource 
measurement.  Of course, one kind of reason is a formal proof.  In this 
context, what one gets is a semantics for Artemov's Logic of Proofs 
(LP), a semantics that can be used to re-establish a number of basic 
results about LP, but from a different direction.  I will present this 
semantics, and sketch how some of the important facts about LP can be 
derived using it.