A few years back I watched a talk by a German linguistics professor where he (IIRC) mentioned a rhetorical technique where the writer of a speech moves certain facts into a secondary position in a sentence, in which the assertion stays as is even if the sentence is negated.
Sadly, I don't remember the exact talk, but I wondered if there is a name for that. Here are two examples:
Everyone knew that he lied about the reasons for war.
There are multiple "assertions" made in this sentence. First that "everyone knew" and second that "he lied". Now if you ask someone to negate that sentence, I think most people would say: "Not everyone knew that he lied about the reasons for war". So most people would only negate the first assertion.
Another example would be:
He felt as exhausted as many working class people feel every day.
Probable negation: "He didn't feel as exhausted as many working class people feel every day", leaving the assertion that working class people that way every day untouched.
Is there a name for those type of assertions or a name for the technique of asserting things in this by-the-way style?