  An original presentation of Categorical Quantum Physics, in the line of
Abramsky and Coecke, tries to introduce only objects and assumptions that are
clearly relevant to Physics and does not assume compact closure. Adjoint
arrows, tensor products and biproducts are the ingredients of this
presentation. Tensor products are defined, up to a unitary arrow, by a
universal property related to transformations of composite systems, not by
assuming a monoidal structure. Entangled states of a tensor product define
mixed states on the components of the tensor product. Coproducts that fit the
adjoint structure are shown to be defined up to a unitary arrow and to provide
biproducts. An abstract no-cloning result is proved.
