theorem
Hex.GraphIso.Nauty.Sparse.node_codes
{n k : Nat}
(G : Sparse.Colored n k)
(hn : 0 < n)
(tcLevel fuel : Nat)
(cs bs fs : List Nat)
(numcells : Nat)
(st : State n)
:
CodeEntry G tcLevel (cs.length + 1) numcells st →
n ≤ cs.length + fuel →
Comparison G.graph cs bs fs st →
have out := (Generic.node false (Graph.ofGraph G.graph) (n + 2) tcLevel fuel (cs.length + 1) numcells st).snd;
∃ (bs' : List Nat), ReturnCodes G.graph cs bs' fs out ∧ Grows (State.key G.graph bs st) (State.key G.graph bs' out)
Every sufficiently bounded native off-path call returns settled code comparisons and never decreases the incumbent. Its proof follows the executed mutual recursion, including skipped siblings and nonlocal exits.