If Object-Role Modeling (ORM) is to be considered a formal theory or system of logic, then the graphical models expressed in ORM must be considered as if they were sentences of formal logic. In other words, the graphical pictures in ORM are analogous to sentences in formal logic because they convey information about the relationships between objects and their properties in a structured way.

ORM is a graphical language that is used to model complex systems and databases. It consists of graphical symbols and notation that are used to represent entities, attributes, relationships, and constraints. The symbols in ORM are used to construct models that describe the structure and behavior of the system being modeled.

To be considered a formal theory or system of logic, ORM must have a well-defined syntax and semantics, and it must be able to represent and reason about information in a structured and consistent manner. The graphical models in ORM can be considered as if they were sentences of formal logic because they convey information about the structure and relationships of the objects being modeled in a structured and consistent way.

In ORM, the graphical symbols and notation are used to represent logical concepts and relationships between objects. The models created in ORM can be analyzed and validated using formal methods, such as logic and set theory. Therefore, the graphical models in ORM can be considered as if they were sentences of formal logic, and the principles of formal logic can be used to reason about the models and to draw valid conclusions from them.