ctivity" -&lt;- "process"
&lt;Option 2&gt; : "process"  -&lt;- "activity"

&lt;Option A&gt; : "activity" -&lt;- "activity class"
&lt;Option B&gt; : "activity occurrence" -&lt;- "activity"

By "maximal number" I mean that each agent, interpreter, user,
or whatever is constrained only by the requirement of logical
consistency among his/her/its choices.

I think that something like this, at least, will be required
if we want to realize that old dream of Leibniz that started
this business -- to devise a common 