6. Define a relationon N by a ~b if and only if ab is a square (a) Show that is an equivalence re...
1. Define a relation on Z by aRb provided a -b a. Prove that this relation is an equivalence relation. b. Describe the equivalence classes. 2. Define a relation on Z by akb provided ab is even. Use counterexamples to show that the reflexive and transitive properties are not satisfied 3. Explain why the relation R on the set S-23,4 defined by R - 11.1),(22),3,3),4.4),2,3),(32),(2.4),(4,2)) is not an equivalence relation.
10. Verify that the relations given below are quasiorders. List the elements of each equivalence class of the induced equivalence relation, and draw the Hasse (a) On the set (1,2,..., 303, define mn if and only if the sum of the digits (b) On the set (1.2,3,4,11, 12, 13,14,21,22,23,24), define mn if and only diagram for the induced partial order on the equivalence classes of m is less than or equal to the sum of the digits of n. if...
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or m, ne N define m- n if m-m is a multiple of 3. (a) Show that-is an equivalence relation on N. &) am siue mo ijk 2 wheh is a uutjle of us p (b) List 4 elements in each of the following equivalence classes [0). I1). [2). 131 141 (c) Find the set of all equivalence classes for this relation
6. Fix n E N and recall the definition of the equivalence relation on Z given by a = b mod n. (This means that a – b = kn, for some k € Z.) Let [a] denote the equivalence class containing a. (a) Show that defining [a] + [b] := (a + b] makes sense, i.e. does not depend on the choice of representatives for the classes. (b) Show that defining [a] × [b] := [a x b] makes...
4. Define a function f:N → Z by tof n/2 if n is even 1-(n + 1)/2 if n is odd. f(n) = Show that f is a bijection. 11 ] 7. Let X = R XR and let R be a relation on X defined as follows ((x,y),(w,z)) ER 4 IC ER\ {0} (w = cx and z = cy.) Is R reflexive? Symmetric? Transitive? An equivalence relation? Explain each of your answers. Describe the equivalence classes [(0,0)]R and...
Problem 5. Define a relation ~on R x R as (x, y) ~(a,b) if and only if either x-a or y- b. Prove or disproof, isan equivalence relation? If so, write down all the equivalence classes.
(b) Let be the relation on N define by a ~ b iff there are m,n e Z+ with albm and bla". Show that is an equivalence relation. on hea infinitolo
Please answer all parts. Thank you!
20. Let R be a commutative ring with identity. We define a multiplicative subset of R to be a subset S such that 1 S and ab S if a, b E S. Define a relation ~ on R × S by (a, s) ~ (a, s') if there exists an s"e S such that s* (s,a-sa,) a. 0. Show that ~ is an equivalence relation on b. Let a/s denote the equivalence class...
(10) Define a relation R on Zn (the integers mod n) as follows: lal isR related to [b (i.e. [an Rbn) iff there is [cn E Gn such that a b (a) Show that R is an equivalence relation on Zn (b) Give all the equivalence classes for R when n-12.
2. Let f : A ! B. DeÖne a relation R on A by xRy i§ f (x) = f
(y). a. Prove that R is an equivalence relation on A. b. Let Ex =
fy 2 A : xRyg be the equivalence class of x 2 A. DeÖne E = fEx : x
2 Ag to be the collection of all equivalence classes. Prove that
the function g : A ! E deÖned by g (x) = Ex is...