Webel: SysML4Mathematica: An Association used as the Type of an argument or return is represented by a Block '<||>'. A List used as as the Type of an argument or return is represented by a Block '{}'. (Extending types may adapt the notation.)

Note that while a SysMLv1.x ValueType can be structured, it can only hold limited types of properties. A Mathematica Association '<||>' or List '{}' can hold any Mathematica expression, so the use of SysML Blocks to represent them is far more flexible.

The MagicDraw SysML Plugin and Magic Model Analyst^® (Cameo Simulation Toolkit^®) tools seem to cope well in most cases with the use of such punctuation characters in Block names, and the characters are easy to prompt on.

Reusable libraries of Activity, OpaqueBehavior, and SysML ConstraintBlock elements may be created to represent Mathematica operations on Associations and Lists, including Map operations, and functional programming (which Mathematica excels at).

Note that either the Association <||> Block or the List {} Block may be extended for dedicated cases, such as: