In mathematical logic, a formula is considered absolute if it has the same truth value in some types of structures (also called models). Theorems about absolutes usually establish the relationship between the absolutes of formulas and their syntactic forms.
There are two kinds of weak partial absolute forms. If the truth value of the formula in each substructure n of structure M comes from the truth value in M, then the formula is downward absolute. If the truth of a formula in a structure n means the truth of the extension n of each structure m, then the formula is upward absolute.
Extended data
The relationship between relativity and absoluteness;
Relativity and absoluteness are the products of logical thinking, which are necessarily the same as contingency. It is precisely because logical thinking produces relative concepts that there are many positions, and there are differences and disputes between people.
Scientifically speaking, any movement and evolution of anything is the inevitable result of the interaction of various factors. So in science, there are only unknown factors and no accidental phenomena. The so-called accident is just an unexpected necessity. If we blindly distinguish between the two concepts of relative and absolute, we will never get a unified understanding.
Marxism is the product of logical thinking and a theory based on a certain position, so it can never unify people's thoughts, even the thoughts of a Marxist political party. It is impossible to completely solve social problems.
To completely solve social problems, we must thoroughly understand all the factors that cause problems and eliminate them one by one, or turn negative factors into positive ones. We should establish a scientific way of thinking.
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