[qsort] more accurate description of imperative two ways partition

sorting/dc-sort/dcsort-en.tex

@@ -908,8 +908,7 @@ \subsubsection{2-way partition}
 equal to the pivot, the situation at this stage is illustrated in figure \ref{fig:partition-2-way} (a).
 
 In order to partition all elements less than or equal to the pivot to the left, and the others to the right,
-we can exchange the two elements pointed by $i$, and $j$. After that the scan can be resumed until either
-$i$ meets $j$, or they overlap.
+we can exchange the two elements pointed by $i$, and $j$. After that the scan can be resumed. We repeat this process until either $i$ meets $j$, or they overlap.
 
 At any time point during partition. There is invariant that all elements before $i$ (including the one
 pointed by $i$) are not greater than