For the example immediately above, what problem, if any, arises with the identifier of IsOn if the participation condition is non-obligatory for (a) Project and (b) Employee? Show that the assignment...

For the example immediately above, what problem, if any, arises with the identifier of IsOn if the participation condition is non-obligatory for (a) Project and (b) Employee?

Show that the assignment of project Name and project Start Date to Is On is equivalent to assigning project No, project Name and project Start Date to Employee as a repeating group, followed by the removal of the repeating group into a separate entity.