In this paper the universal structural type of entities is presented by recursive applications of two operators, i.e., operator which constructs positioned subsets of entity name universum and operator which constructs a functional set on the entity name universum. The object subtype is determined using an especial commutational diagram with the compositions of inner functions. The main integration rule of conceptual object–relationship–property scheme is determined by means of external containment function. A compositions of inner and external functions serve as a tool for normalization of entities systems. The advantages of proposed approach to the modelling of entities system are pointed out.