Joint asymptotic normality of the DFS variables

Let $T$, $B$, $F$, and $C$ be the four random variables defined in the depth-first search analysis of the random digraph. Joint asymptotic normality conjecture. All four variables $T,B,F,C$ are jointly asymptotically normal. The text notes that $T+F$ and $B+C$ are asymptotically normal by the central limit theorem, but does not establish joint asymptotic normality of all four variables.