Is a constant difference a controlled constant?

Relevant answers:

Difference between pointer to constant and constant pointer?
1. pointer to a constant means you can not change what the pointer points to 2. constant pointer means you can not change the pointer.
What is the difference between ordinary constant and an arbitrary constant?
Simple constant is a fixed value which can not change but an arbitrary constant is also a value which can be changed for different functions.
Difference between permeability constant and permittivity constant?
Permittivity is the measure of access of electric field in any medium while the other is the same of magnetic field in any medium.This is because of symmetry between the electric field and magnetic...
What is the difference between constant and non-constant motion?
Acceleration is the difference between constant and non-constant motion.
What is difference between simple constant and arbitrary constant?
Constant is just a value, a fixed value that doesn't change. And arbitrary constant is a value that is fixed throughout multiple functions you pick for ease of calculations.