 The definition of the amount of information in a number in therms of logarithms allows us to classify other mathematical functions in terms of their capacity to process information. The Information Efficiency of a function is the difference between the amount of information in the input of a function and the amount of information in the output (Adriaans 2016  [OIR]).  It allows us to measure how information flows through a set of functions. We use the shorthand \(f(\overline{x})\) for \(f(x_1,x_2,\dots,x_k)\):