 First, some terminology. A machine m will be said to be able to generate a certain function (e.g., x squared) if m can be set up so that if m is presented with any of the function’s arguments (e.g., 4), m will carry out some sequence of processing steps, at the end of which m produces the corresponding value of the function (16 in the example). Mutatis mutandis for functions that, like addition, demand more than one argument.