theorem
Hex.GraphIso.Nauty.Sparse.FirstRef.target
{n : Nat}
{G : SparseGraph n}
{tcLevel base level : Nat}
{root current : RefineSt n}
{st : State n}
(h : FirstRef G tcLevel base root st)
(hdepth : level ≤ h.last)
(hr : RefineSt.Ready G base root)
(hc : RefineSt.Ready G level current)
(hshape : NodeShape n base root.ptn)
(hp : FollowsPerm G st.firsttc base root level current)
(hopen : discreteAt current.ptn level n ≠ true)
:
Int.ofNat (targetcell (Graph.ofGraph G) current.lab current.ptn level tcLevel (-1)) = st.firsttc[level]!
A live stored-target descent below a cheap ancestor chooses the exact saved next target, even after sibling searches reorder the current cells.