Wrong syntax for the formal owl:equivalentClass axiom of coos:Phase and coos:SubProcess

Here: https://github.com/linked-statistics/COOS/blob/master/coos.ttl#L92

and here: https://github.com/linked-statistics/COOS/blob/master/coos.ttl#L104

Only a single value is displayed in Protégé:

![image](https://github.com/linked-statistics/COOS/assets/2728945/2ef91c05-03a7-43e9-9f9b-34eff7eb2e97)

I will propose a PR