This monograph gives a logical treatment of two centralaspects of the concept of information, namely informationprocessing and information structure. The structure ofinformation is treated as a topic in model theory, whileinformation processing is seen as an aspect of proof theory. A wide spectrum of substructural subsystems ofintuitionistic propositional logic and of Nelson'sconstructive logic with strong negation is investigated. Inparticular, the problems of cut-elimination, functionalcompleteness, and coding of proofs with lambda-terms arehandled. Finally, an interpretation of these systems interms of states of information and operations over thesestates is presented.