# 8.20.3.18 IfcVertex

## 8.20.3.18.1 Semantic definition

Informal Propositions:

1. The vertex has dimensionality 0. This is a fundamental property of the vertex.
2. The extent of a vertex is defined to be zero.

## 8.20.3.18.4 Formal representation

ENTITY IfcVertex
SUPERTYPE OF (ONEOF
(IfcVertexPoint))
SUBTYPE OF (IfcTopologicalRepresentationItem);
END_ENTITY;