- INSTANCE: Graph , edge costs , a tree on disjoint to .
- SOLUTION: A tree in G such that , , and is 2-edge-connected.
- COST FUNCTION:
- OBJECTIVE: Minimize.
*Approx.:*Approximable within [38].*Hardness:*NP-hard to approximate for trees with radius [50].

2015-04-27 Revision: 288 PDF version