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:
— data types;
— constraints on instances of the data types.
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.