the.com/derivation
Proof wearing a trench coat, revealing itself one logical step at a time.
means The step-by-step chain of reasoning (or word history) that shows how you got from a starting point to a conclusion — the 'show your work' of logic or language.
from From Latin derivare, 'to lead or draw off,' originally used of water: diverting a stream (rivus, 'river' or 'brook') away from its main channel via a side-channel (de-, 'away from' + rivus). The image carried into Old French and then English, where by the 1500s it described tracing how a word, idea, or conclusion had been 'channeled off' from an original source — knowledge flowing step by step from its headwaters to wherever it ends up.
- not a proof
- proof shows truth, derivation shows the path
- etymology
- from Latin rivus, a stream branching off
- logic use
- each line must follow by a named rule
- linguistics twist
- also means birthing cat from feline, suffix style