  The equivalence of two conditions on the primitive elements in an
$SL(2,\mathbb C)$ representation of the free group $F_2 = <a,b>$, namely
Minsky's condition of primitive stability and the $BQ$-conditions introduced by
Bowditch and generalised by Tan, Wong and Zhang, has been proved by Lee and Xu
and independently by the author in arXiv:1901.01396. This note is a revised
version of our original proof, which is greatly simplified by incorporating
some of the ideas introduced by Lee and Xu, combined with the language of the
Bowditch tree.
