Editing Object–role modeling (section)

=== Facts ===
Object–role models are based on elementary facts, and expressed in [[diagram]]s that can be verbalised into natural language. A fact is a [[proposition]] such as "John Smith was hired on 5 January 1995" or "Mary Jones was hired on 3 March 2010".

With ORM, [[proposition]]s such as these, are abstracted into "fact types" for example "Person was hired on Date" and the individual propositions are regarded as sample data.  The difference between a "fact" and an "elementary fact" is that an elementary fact cannot be simplified without loss of meaning. This "fact-based" approach facilitates modeling, transforming, and querying information from any domain.<ref name="orm.net">{{Cite web | url=http://www.orm.net/pdf/ORM2_TechReport1.pdf | title=ORM 2 Graphical Notation | access-date=2024-05-19}}</ref>