[t]he symbolic representation of a process or operation performed against one or more operands in an expression, such as "+" (plus, or addition) and ">" (greater than). When evaluated, operators return a value as their result. If multiple operators appear in an expression, they are evaluated in order of their operator precedence.
(a) Among the several States or with 1 or more foreign nations;
(b) In any territory of the United States or in the District of Columbia, or between any such territory and
(1) Another such territory, or
(2) Any State or foreign nation; or
(c) Between the District of Columbia and any State, territory, or foreign nation. This definition does not include any nonprofit entity that would otherwise be exempt from coverage under Section 5 of the Federal Trade Commission Act (15 U.S.C. §45).