“…In addition, they gave an infinite family of instances on paths that satisfy their sufficient condition and whose transformation requires Ω(n 2 ) intermediate L-edge-colorings. As the authors mentioned in [9], their sufficient condition is motivated by the well-known "list coloring conjecture" [11]: it is conjectured that any graph G has an L-edgecoloring if |L(e)| ≥ χ (G) for each edge e, where χ (G) is the chromatic index of G, that is, the minimum number of colors required for an ordinary edge-coloring of G. This conjecture has not been proved yet, but Borodin et al [2] proved that any bipartite graph, and hence any tree, has an L-edgecoloring if |L(e)| ≥ max{d(v), d(w)} for each edge e = vw. In this sense, there is a gap between the two sufficient conditions [2] and [9]: from the sufficient condition of [9] we cannot say anything about the reconfiguration if a given tree T has an edge e = vw with |L(e)| = max{d(v), d(w)}, whereas T has L-edge-colorings.…”