說出口的不
最貼近核心畫面的一支：說不的是一個人。
noun · C1
The act of saying no, or of showing that you do not agree. It covers a spoken refusal and a silent sign such as a shake of the head.
否認；表示不同意
核心畫面
You can think of negation as the moment a no is produced. Someone shakes their head, or a word like not is dropped into a sentence, or an action quietly cancels a promise. In every case something that was standing is pushed over, and what is left is the not-version of it.
negation 的核心畫面可以想成「把『不』放出去的那一刻」。可能是一個人搖頭，可能是一句話裡塞進一個 not，也…更多收起
negation 的核心畫面可以想成「把『不』放出去的那一刻」。可能是一個人搖頭，可能是一句話裡塞進一個 not，也可能是一個做法把原本的承諾抹掉。不管哪一種，原本立著的東西被推倒，留下來的是它的「不」版本。整組意思就像從這個畫面長出來：先是人說不，再來是事情被說成不，最後是語言和邏輯裡那個專門負責說不的位置。From the word’s history
From Latin negātiō, a denial or a word meaning no, on the verb negāre, to say no; into English through Old French negacion and Middle English negacioun. By parts it is negate plus -ion.
依照證據裡的詞源，negation 來自拉丁文 negātiō（否認、表示「不」的字），底下是動詞 negāre「說不」，再經古法文 negacion、中古英文 negacioun 進入英文；拆字則是 negate＋-ion。這條線正好落在核心畫面上：這個字的老家就是「說不」。
Wiktionary entry for negation (source_ref kaikki:3f6f69a190036ae4:1006440471), etymology_text supplied in the evidence packet
Three branches
被做法抵銷的不
把「說不」的主角從人換成事：這次說不的不是嘴巴，是做法。
noun · C1
The cancelling out of something, so that it has no effect any more, or is even turned into its opposite. It is often used when an action destroys the very thing it was supposed to support.
否定；抵銷
語言和邏輯裡的不
同樣是說不，但這裡把「不」做成了可以操作的形式：一個步驟、一個符號、一個字。
noun · C1
In logic and language study, the opposite version of a statement, made by putting not into it. The word also names the operation of forming that opposite.
否定句；否定運算