 ASteiner subgraph of (G, W) is a subgraph of G that contains all vertices of W and there is a path between every pair of vertices of W in the subgraph.
<clarity>  ASteiner subgraph of (G, W) is a subgraph of G that contains all vertices of W and there is a path between every pair of vertices of W in the subgraph.
 A of (G, W) is a subgraph of G that contains all vertices of W and there is a path between every pair of vertices of W in the subgraph.