Object-Role Modeling (ORM) does not support negation, and this can make it challenging to directly map ORM models to first-order logic.

In general, negation is an important component of first-order logic, as it allows us to express properties that are not satisfied by certain objects or sets. Without negation, it can be difficult to express the full range of properties and constraints that we may want to describe in a logical system.

However, it is still possible to map ORM models to a first-order theory that does not include negation. This results in a limited logical system that is not able to express all of the properties and constraints that could be expressed in a full first-order theory.

Alternatively, it is also possible to map ORM models to other logical systems that do not rely on negation, such as modal logic or description logic.