theorem
Hex.GraphIso.Nauty.Max.NodeInput.first_best
{n k : Nat}
{G : Colored n k}
{ctx : Ctx n}
{tcLevel fuel : Nat}
{f : Frame n}
{bs fs : List Nat}
{parents : Parents n}
(h : NodeInput G ctx tcLevel fuel true f bs fs parents)
(hd : (Generic.prepareFirst ctx tcLevel f.level f.numcells f.entry).fst = n)
:
SearchState.best ctx
(firstterminal f.level (Generic.prepareFirst ctx tcLevel f.level f.numcells f.entry).snd.snd.snd.snd) = some (Frame.key ctx tcLevel f)
Installing the first discrete leaf records precisely its frozen specification key, including the incoming refinement-code prefix.
The first discrete branch completes the node without invoking its sweep continuation.