in the theory, an n-ary function over the domain is assigned To each n-ary predicate symbol in the theory, an n-ary relation over the domain is assigned. In the intended interpretation, the domain of individuals consists of views, such as production; entities, such as part and vendor; domains, such as qty_on_hand; connection relationships; category clusters; and so on. If every axiom in the theory is true in the interpretation, then the interpretation is called a model for the theory. Every model for the IDEF1X theory corresponding to the IDEF1X meta model and its constraints is a valid IDEF1X model. See also Conceptual model (computer science) Crow's foot notation ER/Studio Enterprise Architect (software) IDEF0 IDEF5 ISO 10303 Logic Works Weak entity References Further reading Thomas A. Bruce (1992). Designing Quality Databases With Idef1X Information Models. Dorset House Publishing. Y. Tina Lee & Shigeki Umeda (2000). "An IDEF1x Information Model for a Supply Chain Simulation". External links ISO/IEC/IEEE 31320-2:2012 FIPS Publication 184 Announcing the IDEF1X Standard December 1993 by the Computer Systems Laboratory of the National Institute of Standards and Technology (NIST). (Withdrawn by NIST 08 Sep 02 see Withdrawn FIPS by Numerical Order Index) Federal Register vol. 73 / page 51276 withdrawal decision Overview of IDEF1X at www.idef.com IDEF1X Overview from Essential Strategies, Inc. Data modeling Data modeling diagrams Data modeling languages Systems analysis