A diagrammatic approach to symmetric lenses

Lenses are a mathematical structure for maintaining consistency between pair of systems. In their ongoing research program, Johnson and Rosebrugh have sought to unify the treatment symmetric lenses with spans asymmetric lenses. This paper presents diagrammatic approach categories, through representing propagation operations Mealy morphisms. The central result this is demonstrate that bicategory locally adjoint lenses, constructing an explicit triple hom-categories.