Price relationship (equivalence relationship).
Let n be a positive integer and define the congruence relation R = {< x, y & gt|n|(x? Y)}, certificate
Ming r is equivalent.
Let R be the equivalence relation on nonempty set A. For any x ∈ A, the set [x] R = {y | y ∈ a, < x, y>∈ R} is the equivalence class of x about r, or the equivalence class of r generated by x, where x is called the generator of [X] R. 。
Let R be an equivalence relation on nonempty set A, and the set of all equivalence classes determined by R is called quotient set on set A, which is denoted as A/R, that is, A/R = {[x]R|x ∈ A}.
In the equivalence relation, we find that the elements in the same equivalence class have the same attributes, so we can set.
The elements in are divided into different categories, corresponding to the division of sets.
Let R be the equivalence relation on nonempty set A, then the quotient set A/R from A to R is a division of A, which is called equivalent division derived from R. 。
Given a partition of set a π= {s 1, S2, ..., SM}, then the relation r = (s1× s1) ∩ (S2× S2) ∩ ∩ (sm× we call this relation r as
Let R be a relation on nonempty set A. If R is reflexive, antisymmetric and transitive, it is said that R is on a..
The partial order relation of is recorded as "?" Replace "less than or equal to" with "and"
Answer? B. Orderly couples