 Such a definition of implementation allows Primiero (2020) to provide a general definition of correctness: a physical computing system is correct if and only if it is characterized by correct implementations at any LoA. Hence correctness and implementation are coupled and defined at any LoA. Functional correctness is the property of a computational system that displays the functionalities required by the specifications of that system. Procedural correctness characterizes computational systems displaying the functionalities intended by the implemented algorithms. And executional correctness is defined as the property of a system that is able to correctly execute the program on its architecture. Each of these forms of correctness can also be classified quantitatively, depending on the amount of functionalities being satisfied. A functionally efficient computational system displays a minimal subset of the functionalities required by the specifications; a functionally optimal system is able to display a maximal subset of those functionalities. Similarly, the author defines procedurally as well as executionally efficient and optimal computational systems.