 Category theory is an extremely powerful tool in its own right. For a thorough introduction see Awodey (2006). For more work on the relationship between various substructural logics and channel theory, see Restall (1994a, 1997, 2006). Further category-theoretic work on information flow may be found in Goguen (2004—see Other Internet Resources). Recent important work on category-theoretic frameworks for information flow that extend to quantifiable/probabilistic frameworks is due to Seligman (2009). Perhaps the most in depth treatment of information flow in category theoretic terms is to be found in the work of Samson Abramsky, and an excellent overview may be found in his “Information, Processes, and Games” (2008). Recent work on the intersection between information as code and information as correlation uses substructural logics (relevance and linear logics in particular) to model logical proofs as information sources themselves. A proof is a source of information par excellence, and the contributions in the area by Mares (2016) are vital.