# Math Help - Relation

1. ## Relation

I am supposed to draw a diagram this is symmetric and antisymmetric, but is not the equality relation =.

So far I can only come up with:

1 <----> 2
^ ^
l l
l l
v v
3<----->4

to show symmetry.

2. I am sorry to tell you that your posting is meaningless.
What is the question in detail?

3. The questions exactly is: Find a relatiom on the set [1,2,3,4] that is symmetric and antisymmetric, but is not the equality relation =.

I was trying draw a picture to show symmetry which would be a double headed arrow between all elements. The diagram for antisymetric means that it is only a one head arrow. I need to try to find a way to do show both relations.

4. Originally Posted by undmath11
The questions exactly is: Find a relatiom on the set [1,2,3,4] that is symmetric and antisymmetric, but is not the equality relation =.

I was trying draw a picture to show symmetry which would be a double headed arrow between all elements. The diagram for antisymetric means that it is only a one head arrow. I need to try to find a way to do show both relations.
What about the empty relation, call it R, on the set S = {1,2,3,4}?
Since S is nonempty, convince yourself that R is irreflexive. This should tell you that R cannot be an equivalence relation.
What now can be concluded about equality?
Convince yourself that R is vacuously both symmetric and antisymmetric (and incidently, transitive).