> An operation is a calculation based on some inputs. Which operations are linear and predictable? Multiplication, it seems.

> Exponents (F(x)=x^2) aren’t predictable: 10^2 is 100, but 20^2 is 400. We doubled the input but quadrupled the output.

I'm struggling to find sympathy for this tortured definition. "Predictability" seems like such poor way to work out an explanation for linearity.