IFC 4.3.x development IfcUnitAssignment Semantic definitions at the entity

IfcUnitAssignment indicates a set of units which may be assigned. Within an IfcUnitAssigment each unit definition shall be unique; that is, there shall be no redundant unit definitions for the same unit type such as length unit or area unit. For currencies, there shall be only a single IfcMonetaryUnit within an IfcUnitAssignment.

NOTE  A IfcProject has a unit assignment which establishes a set of units which will be used globally within the project, if not otherwise defined. Other objects may have local unit assignments if there is a requirement for them to make use of units which do not fall within the project unit assignment.

HISTORY  New entity in IFC1.5.1. Attributes

#Attribute Type Description
1Units SET [1:?] OF IfcUnitUnits to be included within a unit assignment. Entity inheritance

dot_inheritance IfcUnitAssignment IfcUnitAssignment Formal representations

ENTITY IfcUnitAssignment;
	Units : SET [1:?] OF IfcUnit;
	WR01 : IfcCorrectUnitAssignment(Units);