SYSML2_ — Missing explicit explanation of compartments as views

There should be explicit specification and explanation, that a diagram and a compartment are views, as well as clarification on how the filter notation can be applied to a view compartment and to a diagram. Consider an extension to the filter notation.

Missing explicit explanation of compartments as views

Elaborate and improve the description in the current Language Specification subclause 7.25 Diagrams to cover "Compartments and Diagrams as View Usages". Move the general discussion of the structure of graphical views from 9.2.19.1 Standard View Definitions Overview to 8.2.3.1 Graphical Notation Overview and expand it, consistent with the description in 7.2.5.