This part of ISO 10303 defines a language by which aspects of product data can be specified.
The language is called EXPRESS.
This part of ISO 10303 also defines a graphical representation for a subset of the constructs in the EXPRESS language. This graphical representation is called EXPRESS-G.
EXPRESS is a data specification language as defined in ISO 10303-1. It consists of language elements which allow an unambiguous data definition and specification of constraints on the data defined.
The following are within the scope:
The following are outside the scope of this part of ISO 10303:
definition of database formats;
definition of file formats;
definition of transfer formats;
process control;
information processing;
exception handling.
EXPRESS is not a programming language.