The coset cursor plays no role in the reach relation.
Every generator recorded by an event is a checked automorphism.
A canonical reference that is a cell permutation of the current labelling at the current level reaches every active ancestor frame and picks the same child there.
What the first-path sweep knows at every cursor position after its
guiding child: the loop invariant, the live package with frame
stabilization, path facts, both reference histories below the loop, the
first-path controls, orbit and coset facts, first-leaf domination, and the
cheap-cell boundary discipline relative to the node entry boundary e.
- inv : LoopInv G ctx tcLevel specFuel level codes bs fs numcells rsLab rsPtn tc len tcell cursor base st best trail
- live : FirstLive ctx level st trail rsLab rsPtn
- path : PathOk ctx (initPtn n (n + 2) (initialPartition G).snd) (initialPartition G).fst level st
- firstTrail : FirstTrail ctx level st trail
- canonTrail : CanonTrail ctx level st trail
- desc : CheapDesc ctx level st.noncheaplevel (LoopInv.frame rsLab rsPtn numcells)
- park : cheapautom rsPtn level n = false → st.noncheaplevel ≠ level
- keep : st.noncheaplevel < level → st.noncheaplevel = e
Instances For
What a finished first-path sweep preserves for its enclosing node.
- boundary : out.noncheaplevel < level → out.noncheaplevel = e
Instances For
The small-cell descent invariant of a child, when the loop boundary is merely known to avoid the loop level.
The small-cell subtree fact at the frozen frame, when the boundary is merely known to avoid the loop level.
The cheap-cell ledger is ready for the next child.
Filtering the live set leaves every other hypothesis unchanged.
The reach relation depends on its input state only through the labelling and partition.
A new canonical reference installed below a child is a cell permutation of the loop labelling at the loop level.
An off-path child that stays at the loop level rebuilds every sweep hypothesis for the recursive tail on the recovered state.
Clearing the request keeps the labelling and partition.
The receiving-loop validity of a child's live short-prune pair, from the child's return bound alone.
Clearing the request exactly when it is raised leaves none.
Both reference histories below the loop after an off-path child, whatever its return.