(1) has no proposition, and the conditional conclusion is negative at the same time, such as A→B, non-A→ non-B.

(2) Non-proposition only negates the conclusion (or judgment word), such as A is B and A is not B. ..

No proposition is a concept in mathematics. Generally speaking, in mathematics, statements expressed by languages, symbols or formulas that can judge truth or falsehood are called propositions.

For two propositions, if the conditions and conclusions of one proposition are the negation of the conditions and conclusions of the other proposition, then the two propositions are mutually negative. If one of them is called the original proposition, then the other is called its negative proposition.

Extended data:

Definition of proposition: A sentence that can judge right or wrong is called a proposition. Among them, statements judged to be true are called true propositions, and statements judged to be false are called false propositions. Every proposition has an inverse proposition. As long as the title of the original proposition is replaced by the conclusion and the conclusion is replaced by the title, the inverse proposition of the original proposition can be obtained. But the original proposition is correct, and its inverse proposition is not necessarily correct.

Propositional form

1. For two propositions, if the conditions and conclusions of one proposition are the conclusions and conditions of the other, 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.

2. 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.

3. For two propositions, if the condition and conclusion of one proposition are the negation of the conclusion and condition of the other proposition, 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.

References:

Baidu encyclopedia-proposition