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Orbit stability: deciding symmetric Nullstellensatz questions at every scale by one finite computation. The machinery behind the ∀m lower-bound program.
A symmetric family (pigeonhole, modular counting) is one formula shape instantiated at every
scale m, with the scale-m symmetric group acting on its variables. At a fixed degree d,
the GF(2) NS dual question — does a degree-d pseudo-expectation exist? — restricted to
invariant functionals collapses onto orbit types: an invariant L is constant on monomial
orbits, an orbit is named scale-independently by its canonical structure (the bipartite
pigeon/hole graph; the block-intersection hypergraph), and one constraint per joint
(multiplier-orbit × generator) representative captures the whole system
(collapsed_dual_system, soundness = the one-line invariance lemma tested in
an_invariant_functional_checked_on_orbit_representatives_is_checked_on_all_generators).
The stability phenomenon: at fixed d the type set stabilizes once every ≤ d-edge structure is
realizable, and the constraint rows’ entries are parities of counting polynomials in m
(binomials — e.g. Count_3’s off-point constraint a + C(n−4, 2)·b₀), hence eventually periodic
in m with period a power of two (Lucas). So the invariant-witness verdict is decidable for
every m from finitely many evaluations — each in-window verdict differentially validated
against the direct orbit-collapsed solver and, where a witness exists, lifted and re-checked by
check_ns_lower_bound_polys with zero trust.
The honest boundary, forced by our own char-2 theorem
(over_gf2_symmetrizing_a_proof_annihilates_when_the_group_is_even): over GF(2) there is no
Reynolds averaging, so “no invariant witness” does not imply “no witness” — Count_3(8)
realizes the gap (an asymmetric witness on the partial-partition support survives where every
invariant candidate dies). Verdicts here are about invariant certificates; a positive verdict
is a sound NS-degree > d lower bound, a negative one is measured against the gap.
Structs§
- Collapsed
Dual - The collapsed dual system at one scale: columns = canonical orbit types of the degree-
≤ dbasis, rows = the distinct type-vectors of the admitted NS generatorsm·g, taken over one multiplier per orbit × every generator (complete by the invariance lemma: the row ofσ(m)·gequals the row ofm·σ⁻¹(g), and the group permutes the generator set). An invariant functionalL(one bit per type,L(∅-type) = 1) is a valid degree-dpseudo-expectation iff it annihilates every row. - Fitted
Count - An integer-valued polynomial in the scale, in the finite-difference (binomial) basis:
value(m) = Σ_k diffs[k] · C(m − base, k). Fitted from consecutive window evaluations; the interpolation certificate is that the difference table vanishes beyond the allowed degree — every window point past the fitting prefix is an exact verification. - ForAll
Verdict - The ∀-scales verdict: the stabilized system plus its per-residue answers and the in-window differential validation record.
- Stabilized
System - The stabilized symbolic system: the window-fitted entry polynomials, evaluable (mod 2) at
every scale — the finite object that decides the invariant-witness question for all
m. - Symmetric
Instance - A symmetric family instantiated at one scale: the variable count, the
GF(2)generator polynomials, the scale’s symmetry generators, the variable → atom-list map that names orbit types scale-independently, and one anchor per generator — the pseudo-structure that pins the generator’s identity for cross-scale row labeling (a pigeon row is anchored by its pigeon, a point generator by its point, a fixed-shape generator by its own monomial structure; anchor atom-lists carry the marker sort255so they never collide with multiplier variables, while their point atoms share the real sorts and relabel consistently with the multiplier’s).
Functions§
- canonical_
structure - The canonical form of a structure: the lexicographically least relabeling, minimized over all sort-respecting point bijections (brute force over the touched points of each sort — bounded by the degree, so a handful of points). This is the scale-independent orbit-type name.
- collapsed_
dual_ system - Build the
CollapsedDualof an instance at degreed. The type column set comes from the bounded orbit quotient (one canonization per orbit); the rows from one multiplier representative per orbit against every generator, each product’s monomials bucketed by cached type. - count_
instance_ linear - Modular counting
Count_qat scalen, linear encoding (Sₙsymmetry acting on theq-subsets): variableeis its block’s points — one sort. The symmetry generators are the adjacent point transpositions, induced onto the edge variables. - count_
instance_ linear_ marked - Modular counting with one marked point — the point-stabilizer instrument. Point
0gets its own sort, so the symmetry drops fromSₙtoStab(0) ≅ Sₙ₋₁(adjacent transpositions of the unmarked points only) and the canonical types automatically distinguish “touches the marked point.” The collapsed dual then decides existence of a marked-invariant witness — a strictly larger search space than the fully-invariant one (everySₙ-invariant functional isStab(0)-invariant), the first refinement rung between “symmetric” and “arbitrary” on the char-2 gap. - decide_
invariant_ witness_ for_ all_ scales - Decide the invariant-witness question at every scale by one finite computation. Build the
labeled entry counts at each window scale (consecutive scales, all post-onset so every label is
realizable throughout), fit each entry as a degree-
≤ max_count_degreeinteger polynomial (the finite-difference certificate — window points beyond the fitting prefix are exact verifications), read off the Lucas period, and solve the fitted system once per residue class. Every window scale is differentially validated: the fitted verdict must equalinvariant_witness_exists_direct’s, and positive verdicts lift tocheck_ns_lower_bound_polys-passing witnesses. Atrueresidue is a machine-decidedNS-degree > degreelower bound for every scale in that class fromonseton — including scales no explicit basis can represent. - invariant_
witness_ exists_ direct - The direct orbit-collapsed solver — the independent validation path. No canonical types, no
representative tricks: every admitted generator
m·g(all multipliers) becomes a constraint, the unknowns are one bit per orbit (constancy imposed directly), plusL(1) = 1. Same mathematical question ascollapsed_dual_system+CollapsedDual::solve, different code path — the two must agree at every scale, which is the machine check that representative completeness and type canonization are right. - labeled_
dual_ counts - The labeled dual entries at one scale:
label → (column type → monomial count)— the raw integer counts before the mod-2 reduction, the objects that are polynomial in the scale. - monomial_
orbits_ bounded - Degree-bounded monomial orbits: the quotient of the degree-
≤ dbasis under the group, walked on the bounded basis (C(n, ≤d)monomials, never2ⁿ) so it scales tonum_vars ≤ 63— the scale windowpolycalc::monomial_orbits’s cube filter cannot reach. - php_
instance_ clause - Pigeonhole at scale
m, clause encoding (thecrate::families::phplayout,Sₘ × Sₘ₋₁symmetry): variablep·holes + his the atom pair(pigeon p, hole h)— two sorts. A pigeon clause (all-positive row) is anchored by its pigeon; a hole pair by its own structure. - php_
instance_ linear - Pigeonhole at scale
m, linear encoding: each pigeon row as the degree-1 generator1 + Σ_h x_{p,h}(never dropped by a degree budget — the fixed-degree questions stay real at everym), plus the hole at-most-one pairs. Same symmetry and atoms as the clause encoding; pigeon-row generators anchored by their pigeon. - php_
instance_ linear_ marked_ hole - Linear-encoded pigeonhole with one marked hole — the hole-stabilizer instrument
(
Sₘ × Stab(h₀) ≅ Sₘ × Sₘ₋₂). Hole0gets its own sort; pigeon symmetry is untouched. - php_
instance_ linear_ marked_ pigeon - Linear-encoded pigeonhole with one marked pigeon — the pigeon-stabilizer instrument
(
Stab(p₀) × Sₘ₋₁). Pigeon0gets its own sort; hole symmetry is untouched.
Type Aliases§
- RowLabel
- A cross-scale row label: the canonical joint structure of
multiplier ⊕ generator anchor. Two (multiplier, generator) pairs with the same label lie in the same joint orbit, so their entry counts must be identical — enforced fail-closed during collection. - Structure
- A monomial’s structure: one atom list per variable it contains, each atom a
(sort, point)pair — pigeonhole variables are[(0, pigeon), (1, hole)], counting variables are the block’s points[(0, a), (0, b), (0, c)]. Two monomials at any two scales have the same orbit type iff their structures agree up to a sort-respecting relabeling of points (canonical_structure).