Exercises $12\mathrm{.}16-12\mathrm{.}19$ are related. Do the exercises in sequence. The following are tentative specifications for scheduling software.

The scheduling software must support the following functions: arranges meetings, schedules appointments, plans tasks, and tracks holidays $($including vacations$).$

The scheduler runs on a network that many users share. Each user may have a schedule. A schedule contains multiple entries. Most entries belong to a single schedule; however, a meeting entry may appear in many schedules.

There are four kinds of entries: meetings, appointments, tasks, and holidays. Meetings and appointments both occur within a single day and have a start time and end time. In contrast, tasks and holidays may extend over several days and just have a start date and end date. Any entry may be repeated. Repeat information includes how often the entry should be repeated, when it starts, and when it ends.

$12\mathrm{.}16(3)$ The following is a list of candidate classes. Prepare a list of classes that should be eliminated for any of the reasons given in this chapter. Give a reason for each elimination. If there is more than one reason, give the main one.

scheduling software, function, meeting, appointment, task, holiday, vacation, scheduler, network, user, schedule, entry, meeting entry, day, start time, end time, start date, end date, repeat information.

$12\mathrm{.}17(3)$ Prepare a data dictionary for proper classes from the previous exercise.

$12\mathrm{.}18(4)$ The following is a list of candidate associations and generalizations for the scoring system. Prepare a list of associations and generalizations that should be eliminated or renamed for any of the reasons given in this chapter. Give a reason for each elimination or renaming. If there is more than one reason, give the main one.

$-$ scheduling software that supports the following functions

$-$ the scheduler runs on a network that many users share

$-$ user may have a schedule

$-$ a schedule contains multiple entries

$-$ entries pertain to a single schedule

$-$ a meeting entry may appear in many schedules

$-$ meetings and appointments both occur within a single day and have a start time and end time

$-$ tasks and holidays may extend over several days and just have a start date and end date.