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What's the meaning of set description? How to explain his concept? Why to express it like this? {xix-3 > 2} what does each letter mean? I really don't know how to express in this way whether certain objects belong to certain conditions, what are certain conditions, and where are certain objects?
Set description method is generally used to express more elements, but not enumeration, so that people can more clearly understand the elements to be expressed; set represents the whole of a range of elements
｛X｜X-3＞2｝
Brackets represent a collection
X represents the unknown to be expressed
︱represents the unknown ∈ R. generally, R can be omitted and written directly as ︱
X-3 ＞ 2 represents the value range of the set
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