An anti-symmetric relationship says that there is no pair of distinct elements of set $A$ which are related by $R$ to the other. A relation is anti-symmetric if for every pair of distinct elements in the domain one of the following situations holds:
- $xRy$, but it is not true that $yRx$
- $yRx$, but it is not true that $xRy$
- Neither $xRy$ nor $yRx$ is true
The Formal definitions of anti-symmetry: $$\require{cancel}\forall x,y \in A, (xRy \rightarrow y\cancel{R}x) \vee (yRx \rightarrow x\cancel{R}y) \rightarrow x \neq y$$
Or the logically equivalent way to express this is: $$ \forall x,y \in A, (xRy \wedge yRx) \rightarrow x = y$$
How do the formal definitions of anti-symmetry show the above statements? Alternatively, how do the formal definitions show that there is no pair of distinct elements of set $A$ which are related by $R$ to the other? From my understanding, it's saying that for a relation to be anti-symmetric, $\require{cancel}(xRy \rightarrow y\cancel{R}x) \vee (yRx \rightarrow x\cancel{R}y)$, then x cannot equal y, and if $(xRy \wedge yRx)$ then x=y. So why does x have to equal y for $(xRy \wedge yRx)$?
Also, I don't see how $xRy \wedge yRx \rightarrow x=y$ shows there is no pair of distinct elements of set which are related by to the other. Can you please explain further?
– GainzNerd Mar 15 '20 at 21:26