Intersection

https://arbital.com/p/set_intersection

by M Yass Aug 6 2016 updated Oct 12 2016

The intersection of two sets is the set of elements they have in common


The intersection of two sets $~$A$~$ and $~$B$~$, denoted $~$A \cap B$~$, is the set of elements which are in both $~$A$~$ and $~$B$~$.

illustration of the output of an intersection

Formally stated, where $~$C = A \cap B$~$

$$~$x \in C \leftrightarrow (x \in A \land x \in B)$~$$

That is, Iff $~$x$~$ is in the intersection $~$C$~$, then $~$x$~$ is in $~$A$~$ and $~$x$~$ is in $~$B$~$.

For example,