Please make sure you've read the intro page about this highly technical trail on the Webel libraries for the Wolfram Language and SysML4Mathematica.
This entire SECTION uses System Modeling Language (v1) notations!
If you are not familiar with SysML and if you are primarily interested in the Webel libraries for the Wolfram Language you may wish to skip to this next SECTION:
However, to fully understand this slide set using Webel SysML4Mathematica (v1) policies and conventions and why some things in the Webel libraries are coded as they are, you do need to understand the SysML modelling recipes introduced here. To learn SysML for MBSE attend the Webel course: