In computer science and engineering, a system acts as a computable function. An example of a specific function could be y = f(x) where y is the output of the system and x is the input; however, most systems' inputs are not one-dimensional. When the inputs are multi-dimensional, we could say that the system takes the form y = f(x_1, x_2, ...) ; however, we can generalize this equation to a general form Y = C(X) where Y is the result of the system's execution, C belongs to the set of computable functions, and X is an input vector. While testing the system, various test vectors must be used to examine the system's behavior with differing inputs.