I know that an infinite set can be partitioned into 2 infinite subsets.
Can one partition an infinite set into finitely many infinite subsets?
Thanks
I know that an infinite set can be partitioned into 2 infinite subsets.
Can one partition an infinite set into finitely many infinite subsets?
Thanks
On
Of course. We do it by induction.
Theorem: If $A$ is an infinite set and $n>0$ is a natural number then we can write $A$ as a disjoint union of $n$ infinite sets.
Proof. For $n=1$ this is obvious, so we actually start with $n=2$.
For $n=2$ we can do it because every infinite set can be split into two infinite sets.
Suppose that we can split $A$ into $n$ parts, $A_1,\ldots, A_n$. Each is infinite, split $A_n$ into $B$ and $C$, and so the partition $A_1,\ldots,A_{n-1},B,C$ is a partition of $A$ into $n+1$ parts. $\square$
Well, if you can do it with 2, you can keep partitioning one of them.