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Levine [3] defines an operator as ``a rule that transforms a given function into another function'' (p. 33). The differentation operator d/dx is an example--it transforms a differentiable function f(x) into another function f'(x). Other examples include integration, the square root, and so forth. Numbers can also be considered as operators (they multiply a function). McQuarrie [1] gives an even more general definition for an operator: ``An operator is a symbol that tells you to do something with whatever follows the symbol'' (p. 79). Perhaps this definition is more appropriate if we want to refer to the $\hat{C}^3$operator acting on NH3, for example.