Un approccio categoriale alla alla teoria dei grafi non orientati

In this paper we give a definition of symmetric graph and non oriented graph on a suitable category and we study t1ic categories SG(C) and NOG(C) associated with these graphs. Particularly we prove: i) NOG(C) is a reflexive subcategory of SG(G). ii) If C is A-complete [A-cocomplete] then SG(C) and NOG(C) are A-complete [A-cocomplete].