Prove there is a bijection φ : R(X) → P(X)












1












$begingroup$


For a set $X$, let $R(X)$ be the set of equivalence relations on $X$ and let $P(X)$ be the set of partitions of $X$. Prove there is a bijection $varphi : R(X) to P(X)$.



Stuck on how to proceed with this. I understand that equivalence relations and partitions are in essence the same. But in terms of writing a proof, I am really lost how to proceed. Any help will be appreciated.










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
    $endgroup$
    – platty
    Dec 11 '18 at 22:52










  • $begingroup$
    In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
    $endgroup$
    – AlexanderJ93
    Dec 11 '18 at 23:09










  • $begingroup$
    See this and this.
    $endgroup$
    – Arnaud D.
    Dec 14 '18 at 16:17
















1












$begingroup$


For a set $X$, let $R(X)$ be the set of equivalence relations on $X$ and let $P(X)$ be the set of partitions of $X$. Prove there is a bijection $varphi : R(X) to P(X)$.



Stuck on how to proceed with this. I understand that equivalence relations and partitions are in essence the same. But in terms of writing a proof, I am really lost how to proceed. Any help will be appreciated.










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
    $endgroup$
    – platty
    Dec 11 '18 at 22:52










  • $begingroup$
    In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
    $endgroup$
    – AlexanderJ93
    Dec 11 '18 at 23:09










  • $begingroup$
    See this and this.
    $endgroup$
    – Arnaud D.
    Dec 14 '18 at 16:17














1












1








1





$begingroup$


For a set $X$, let $R(X)$ be the set of equivalence relations on $X$ and let $P(X)$ be the set of partitions of $X$. Prove there is a bijection $varphi : R(X) to P(X)$.



Stuck on how to proceed with this. I understand that equivalence relations and partitions are in essence the same. But in terms of writing a proof, I am really lost how to proceed. Any help will be appreciated.










share|cite|improve this question











$endgroup$




For a set $X$, let $R(X)$ be the set of equivalence relations on $X$ and let $P(X)$ be the set of partitions of $X$. Prove there is a bijection $varphi : R(X) to P(X)$.



Stuck on how to proceed with this. I understand that equivalence relations and partitions are in essence the same. But in terms of writing a proof, I am really lost how to proceed. Any help will be appreciated.







equivalence-relations set-partition






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 11 '18 at 22:51









platty

3,370320




3,370320










asked Dec 11 '18 at 22:47









Nihar GuptaNihar Gupta

61




61








  • 2




    $begingroup$
    You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
    $endgroup$
    – platty
    Dec 11 '18 at 22:52










  • $begingroup$
    In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
    $endgroup$
    – AlexanderJ93
    Dec 11 '18 at 23:09










  • $begingroup$
    See this and this.
    $endgroup$
    – Arnaud D.
    Dec 14 '18 at 16:17














  • 2




    $begingroup$
    You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
    $endgroup$
    – platty
    Dec 11 '18 at 22:52










  • $begingroup$
    In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
    $endgroup$
    – AlexanderJ93
    Dec 11 '18 at 23:09










  • $begingroup$
    See this and this.
    $endgroup$
    – Arnaud D.
    Dec 14 '18 at 16:17








2




2




$begingroup$
You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
$endgroup$
– platty
Dec 11 '18 at 22:52




$begingroup$
You say that they are in essence the same -- can you show in what way this holds? That is, if I give you an equivalence relation, can you come up with its corresponding partition and vice versa? This would define such a $varphi$, it then remains to show that it is a bijection.
$endgroup$
– platty
Dec 11 '18 at 22:52












$begingroup$
In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
$endgroup$
– AlexanderJ93
Dec 11 '18 at 23:09




$begingroup$
In addition to platty's advice, it might help to write down exactly what an element of $R(X)$ and an element of $P(X)$ might look like.
$endgroup$
– AlexanderJ93
Dec 11 '18 at 23:09












$begingroup$
See this and this.
$endgroup$
– Arnaud D.
Dec 14 '18 at 16:17




$begingroup$
See this and this.
$endgroup$
– Arnaud D.
Dec 14 '18 at 16:17










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