# binary tree

## Characterizing (aleph_0,aleph_1)-graphs ★★★

Call a graph an $(\aleph_0,\aleph_1)$-\emph{graph} if it has a bipartition $(A,B)$ so that every vertex in $A$ has degree $\aleph_0$ and every vertex in $B$ has degree $\aleph_1$.
\begin{problem} Characterize the $(\aleph_0,\aleph_1)$-graphs. \end{problem}