Consider the Presentation Layer ER diagram that appears in Figure 4.21.
a. What makes SCHOOL part of the specialization lattice involving SCHOOL, NOT_FOR_PROFIT_ORGANIZATION, and PUBLIC_SCHOOL, and, at the same time, part of the SPONSOR category that involves CHURCH, SCHOOL, and INDIVIDUAL? What role (i.e., subclass, superclass, category, aggregate) do SCHOOL and NOT_FOR_PROFIT_ORGANIZATION serve in each of these structures?
b. Does SPONSOR take the form of a total category or a partial category?
c. Is it possible to redraw the SPONSOR category as a specialization and still retain the participation of SCHOOL in the specialization? If the answer is "yes," redraw this portion of Figure 4.21.