C.Bloggs, most sincere apologies.
I only read your first sentence though not as a pre-condition the way you placed it but as a statement. It seemed to re-inforce the OPs initial confusion. Instead, your post #3 says all that is needed.
And love your graphics!
Contributing factor: Often I don't read your posts carefully on known topics because you are simply right and the adrenaline rush of disagreement is never there [human factors, subconscious]
Update to training syllabus: Adopt brevity as a teaching technique [Standards development]
Safety recommendation: Do not post before breakfast. [Operational]