The WRSA oversees several sports. Each sport has a unique name, the number of referees required

to referee matches of that sport, and a list of locations where the sport can be played. For simplicity,

each location is a single string. The WRSA is comprised of many teams. Each team plays exactly

one sport, and every sport has some team associated with it$.$ Each team has a unique name. A team

may choose to have one or more coaches. However, since the WRSA is recreational, teams are not

required to have a coach. Coaches have a name, address, phone number, and certification date.

Players who are registered in the WRSA are members of teams. Each player can be a member of

multiple teams, but they must be a member of at least one team. Players have a name, age, phone

number, and address. Coaches and players are covered by the WRSA$$s insurance and each have

an insurance number. Each player must have at least one emergency contact. The emergency

contacts each have a name, address, relation to the player, and phone number. A player cannot be

a coach and cannot have two emergency contacts with the same name. The WRSA selects several

players to act as mascots. Each mascot must have a nickname. Every team plays in matches with

other teams. A match is given a unique match number, a location, and a date and time. Matches

are always between two different teams and the outcomes are not recorded. Each match is refereed

by other players who are not involved in that specific match.