Complex Elements.

Complex elements are composed of two or more visual elements (primitive or complex). Like primitive elements, complex elements have attributes.

Primitive Elements are intended to be be common to all visual agents. Unlike primitive elements, many complex elements can be domain-specific, and differ from agent to agent.

The following is a first pass at what the complex elements might be based on an examination of Craig's diagram data.

1. Multiple-pass line
2. Dual line arrow
3. Semi-circle
4. arrowhead-isosoles-triangle
5. arrow-curve
6. arrow-line
7. fringe
8. two-line line
9. curly-cue
10. shading
11. dotted line
12. wiggly line
13. circle
14. dotted circle
15. dotted curve
16. curved fringe
17. box
18. curly braces
19. zig-zag
20. cylinder
21. box door closed
22. box door open
23. line door closed
24. line door open
25. triangle
26. text alphabet