aGraduate School of Science & Technology, Kobe University, Nada, Kobe 657-8501, Japan
bDepartment of Earth & Planetary Sciences, Faculty of Science, Kobe University, Japan
Abstract:
Two ideas in theoretical biology, ‘decomposition into functions’ and ‘gluing functions’, are formalized as endofunctors on the category of directed graphs. We prove that they constitute an adjunction. The invariant structures of the adjunction are obtained. They imply two biologically significant conditions: the existence of cycles in finite graphs and anticipatory diagrams.