Let $G = (V,E)$ be an $n$-vertex graph, let $R$ be a finite set (to be specific, let us assume that $R = [n]$), and let $W : V \rightarrow 2^R$. Let us call the pair $(G, W)$ a set-weighted graph.
Now let us consider the following problem, which I'll call the Smallest Set Path problem. The problem is given a set-weighted graph $(G,W)$ and two vertices $s$ and $t$ of $G$, find a path $P$ between $s$ and $t$ such that the union of the sets associated with the vertices of the path has the minimum possible cardinality, i.e. $\bigcup_{v \in P} W(v)$ is minimized.
My specific questions:
- Was the Smallest Set Path problem studied in the literature?
- Was the model of set-weighted graphs as described above considered in the literature in other contexts?