How is the binary relation calculated? R1={(a,b),(c,d)},R2={(b,c),(d,e)} So R1 * R2 = {(a, c)}, R2 * R1 = {(B, d)} What do I think, R1 * R2 = {(a, c), (C, e)}, Because (a, b) (B, c) can get (a, c) (C, d) (D, e) can get (C, e)

R1 = {(a, b), (C, d)}, R2 = {(B, c), (D, e)} according to the definition of binary relation composition, R1 · R2 should find out the common element which is the first element in R1 and the second element in R2, that is, C, and then recombine the remaining elements in R2 and the remaining elements in R1

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1. Discrete mathematics problem, let R be a binary relation on a, define s = {(a, b) | &; C ∈ a, (a, c) ∈ R, (C, b) ∈ r}, prove Let R be a binary relation on a, define s = {(a, b) | &; C ∈ a, (a, c) ∈ R, (C, b) ∈ r}, prove that if R is an equivalence relation on a, then s is also an equivalence relation, and S = R It's OK to connect~
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