1.0 Purpose.- 2.0 Approach.- 2.1 CAD modelling and data storage.- 2.2 Steps taken in the development of the file specification.- 2.3 The finite State machine approach.- 3.0 Basic Principles.- 3.1 Relationships between operating systems and CAD.- 3.2 Informal description of the CAD data schema.- 3.3 Basic concepts for the physical layer.- 4.0 Schema Specification.- 4.1 The high level data specification language HDSL.- 4.2 The formal CAD?I-WG2 schema.- 4.3 Informal description of the schema semantics.- 4.4 Levels of schema implementations.- 5.0 The Physical Layer.- 5.1.1 The physical level.- 5.1.2 The metafile level.- 5.1.3 The alphabet level.- 5.1.4 Tokens of the neutral file language.- 5.1.5 The Statement level.- 5.1.6 Rules for translating from the HDSL into BNF.- 5.1.7 Structure of the neutral file language.- 5.1.8 Arithmetic expressions.- 6.0 Definition of the Neutral File Semantics.- 6.1.1 Interpreter.- 6.1.2 World.- 6.1.3 Entity with scope (except World).- 6.1.4 Entity without scope.- 6.1.5 Property or relation definition.- 6.1.6 Interpretation of argument lists (except references).- 6.1.7 References.- 6.2 Examples of error messages.- 7.0 State Lists.- 8.0 Fortran Binding.- 8.1 General approach.- 8.2 Mapping of HDSL data types onto FORTRAN.- 8.3 Subroutines for interrogating a data base.- 8.4 Subroutines for writing entities into a data base.- 8.5 Subroutines for writing entities onto the neutral file.- 8.6 Subroutines for interrogating a neutral file.- 9.0 Comments on Pre-Processors.- 10.0 Comments On Post-Processors.- Appendix A. The Graphical Alphabet.- Appendix B. The Escape Sequences.- B.1 The Latin alphabet (ISO6937).- B.2 The Greek alphabet.- B.3 The Kanji alphabet.- Appendix C. A Neutral File for Fixed Format Letters.- Appendix D. How this PaperDeveloped.- D.5 ISO/TC184/SC4/WG1 meeting December 1985.- D.7 Special meeting on processor development.- D.8 Common workshop of WG1, WG2, and WG3.- D.9 Common workshop of WG2, WG6, and WG7.- D.10 ISO/TC184/SC4/WG1 meeting March 1986.
