If you define WIDTH and ITER prior to execution you are just giving arguments to your program. Maybe using the term "environment" was not the best choice; what

If you define WIDTH and ITER prior to execution you are just giving arguments to your program. Maybe using the term "environment" was not the best choice; what I mean is that WIDTH and ITER are program variables that impact program behavior and output (appear in regexes etc.) whereas (most) C programs don't actually reference or depend on the pointer width (other than crashing if it's too small); it is an internal detail of the C compiler and underlying hardware that only happens to be visible to the programmer due to leaky abstractions. I don't think those are comparable.