Several telephone companies now offer relay services in which operators, equipped with conventional telephone equipment and telecommunications devices, serve as go-betweens.
Other operators served the airport on a charter basis then.
Command posts where human operators serve electronic brains.
Raising and lowering operators serve as relations between these discrete states.
In principle, the governments guarantee that the operators serve their constituents, and receive a small fraction of the operator's gross income.
Thus, in Scheme, there is no need for a separate "null coalescing operator", because the operator serves that purpose.
The operator serves as a linear function which acts on the states of the system.
The presuppositional operator thus serves as a relevance operator as well.
Each operator also served as a liaison to one of the existing elite counter-terrorism teams from around the world.
Two fixed-base operators also serve the Metro facility with various charter flights.