Can subtraction be defined as the inverse function of addition?
Can you define adding 1 to be: f(x) = x + 1 and then define subtracting 1 as the inverse function, f^-1(x) ? (Provided you proceed to define addition inductively)
Actually some books do talk about x+1 as being the "sucessor function" so maybe it's helpful to think of the operations as functions instead of separate ideas