complex grouping and nesting

Let’s finally model the various jurisdictions. We would like to specify that certain properties of the traffic light system are required or prohibited in a given country or continent. To model specific choices of a jurisdiction we use clafer nesting (existence of a child clafer implies existence of the parent) as well as clafer and group cardinalities.

First, we use xor to allow exactly one of Europe, NorthAmerica, Australia, and NewZealand. Since certain properties are specific to UK we can single it out as a child of Europe. This way, all properties relevant to Europe will also hold since an instance of Europe must exist for an instance of UK to exist. We use mux (meaning 0..1) for NorthAmerica since we might choose a specific country (USA or Canada) or remain unspecific and only choose NorthAmerica.

How many choices for a jurisdiction does our model allow? Are they what you would expect?

Is it possible to have an instance as follows? Why?

Jurisdiction
    Europe
        UK
    NorthAmerica

Let’s use the ClaferConfigurator to generate all instances.

Why do you sometimes see two green ticks in a single column?

Close the Configurator and move to the page linking the jurisdiction and the system.

1. minimal traffic lights
2. adding variability
3. grouping choices