$M \le W,\; \le \tipdy$ and merge $\tipdy$ into $W$.
That is, use $\alg{Merge}$ with $L = W,\; R = \tipdy$.
$M \le W,\; \le \tipdy$ and merge $\tipdy$ into $W$.
That is, use $\alg{Merge}$ with $L = W,\; R = \tipdy$.
\item For each $S \in S^{\pcn}_i$, merge it into $W$.
That is, use $\alg{Merge}$ with $L = W,\; R = S,\; M = M^{\pcn}_i$.
\item For each $S \in S^{\pcn}_i$, merge it into $W$.
That is, use $\alg{Merge}$ with $L = W,\; R = S,\; M = M^{\pcn}_i$.