Entropic Hopf Algebras and Models of Non Commutative Logic
Abstract
We give a definition of categorical models for the multiplicative fragment of non-commutative logic, which we call {\it entropic categories}. We demonstrate the soundness and completeness of our axiomatization with respect to cut-elimination. We then focus on several methods of building entropic categories. The first method is constructed via the notion of a {\it partial bimonoid} acting on a cocomplete category. We also explore an entropic version of the Chu construction, and apply it in this setting. It has recently been demonstrated that Hopf algebras provide an excellent framework for modelling a number of variants of multiplicative linear logic, such as commutative, braided and cyclic. We extend these ideas to the entropic setting by developping a new type of Hopf algebra, which we call {\it entropic Hopf algebras}. We show that the category of modules over an entropic Hopf algebra is an entropic category.Several examples are discussed, based first on the notion of a {\it bigroup}.