I'm currently taking an introduction course to databases and I've come across a problem not described in the textbook.

I'm wondering about the use of cardinality with the use of specialization in enhanced entity-relationship (EER) diagrams.

The case is that I wish to have e.g. a Team which has to have one and only one leader (a designated role). However the Team also consist of other roles. In total each Person can only have one role in the team.

I can't seem to figure out how to draw this up from the description of EER diagrams in my textbook. Am I, by the standardization, allowed to draw min-max pair for the arrows in specializations? Or is there another way to make conditional relationships.

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