Negation of "all yes": If there are three people, then the situation is divided into: one person is, two people are, three people are (all yes) and zero people are (none), then the negation of "all yes" is to exclude the situation of three people, and then "not all yes" (literally, we know that it is definitely not all yes.
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For two propositions, if the conditions and conclusions of one proposition are the conclusions and conditions of another proposition, then these two propositions are called reciprocal propositions, one of which is called the original proposition and the other is called the inverse proposition of the original proposition.
For two propositions, if the conditions and conclusions of one proposition are the negation of the conditions and conclusions of the other, then these two propositions are called mutually negative propositions, one of which is called the original proposition and the other is called the negative proposition of the original proposition.