Connection maps are used during the symbol notification process as a way to keep track of the connection and port pairs that have been traversed. The symbol notification process sends messages through a set of connections as a way to inform a symbol’s dependent symbols that an event has occurred. For example, when a symbol is moved, any link symbols that are connected to it must be notified of the move so that they can take appropriate action. The connection map ensures that circular dependencies do not result in endless recursion.