# RRLS v0.18 — Algebraic Rank Wall

## Status

**P = NP is not proved.**

v0.18 identifies an exact global fiber-occupancy invariant for Boolean CNF and then
measures the cost of making it complete.

---

## 1. Exact Boolean Nullstellensatz rank

Encode each clause C by the polynomial p_C over GF(2) that equals 1 exactly on Boolean
assignments falsifying C. Work in the Boolean quotient

    x_i^2 = x_i.

Let M_d(F) contain the coefficient vectors of all monomial multiples

    m * p_C

whose resulting multilinear degree is at most d.

Then a degree-d algebraic UNSAT certificate exists exactly when

    1 is in RowSpan_GF(2)(M_d(F)).

At full Boolean degree n this hierarchy is complete for finite Boolean formulas.

The implementation was checked against brute force on 30 small random CNFs:

    30/30 exact agreement.

So this is not a heuristic score. A positive row-span result is an exact UNSAT
certificate in the implemented Boolean-ring system.

---

## 2. Measured degree wall

| family         |   scale |   cases |   variables |   clauses |   median_degree |   capped |   median_last_rows |   median_seconds |
|:---------------|--------:|--------:|------------:|----------:|----------------:|---------:|-------------------:|-----------------:|
| 3XOR-as-CNF    |       8 |       1 |           8 |        44 |             3   |        0 |          148       |      0.00281944  |
| 3XOR-as-CNF    |      10 |       1 |          10 |        52 |             3   |        0 |          178       |      0.00749049  |
| 3XOR-as-CNF    |      12 |       1 |          12 |        60 |             3   |        0 |          205       |      0.013766    |
| 3XOR-as-CNF    |      14 |       1 |          14 |        68 |             3   |        0 |          231       |      0.0242567   |
| pigeonhole-raw |       3 |       1 |           6 |        12 |             3   |        0 |          195       |      0.000592117 |
| pigeonhole-raw |       4 |       1 |          12 |        34 |             5   |        0 |        21304       |      0.0731891   |
| pigeonhole-raw |       5 |       1 |          20 |        75 |           nan   |        1 |            1.5e+06 |     20.8388      |
| random3-unsat  |       8 |       2 |           8 |        40 |             4   |        0 |          810       |      0.00737787  |
| random3-unsat  |      10 |       2 |          10 |        50 |             4.5 |        0 |         3236.5     |      0.0335715   |
| random3-unsat  |      12 |       2 |          12 |        60 |             4.5 |        0 |         5634       |      0.0891992   |
| random3-unsat  |      14 |       2 |          14 |        70 |             5   |        0 |        15075       |      0.278859    |

Notable observations:

- globally inconsistent 3-XOR encoded as CNF refuted at degree 3 throughout the tested
  sizes;
- random UNSAT 3-SAT required degree 4–5 in the tested range;
- raw pigeonhole rose from degree 3 (3 pigeons) to degree 5 (4 pigeons);
- the 5-pigeon / 4-hole encoding has 20 Boolean variables and did not refute by the
  degree-7 run before hitting the 1,500,000-row cap.

The last item is a resource-capped experiment, not a degree lower-bound proof.

---

## 3. Why degree is the computational coordinate

The degree-d Boolean monomial feature space has

    N(n,d) = sum_(i=0)^d binom(n,i)

coordinates.

For fixed d:

    N(n,d) = n^O(d),

so constant degree gives polynomial-size linear algebra.

For d growing proportionally with n, the feature space is exponential.

Thus this rank formulation transforms SAT into a very precise question:

> Can every UNSAT instance be canonically represented/refuted in a polynomial-size
> algebraic feature space?

Polynomial Calculus / Nullstellensatz lower-bound theory shows that high degree is
required for important formula families, so the answer is no for this fixed algebraic
proof language.

---

## 4. Affine Rotation Invariance — exact theorem

Let phi be an invertible affine transformation of Boolean GF(2) coordinates.

Suppose F has a degree-d certificate

    sum_i q_i f_i = 1

with every product q_i f_i of degree at most d.

Apply phi:

    sum_i phi(q_i) phi(f_i) = 1.

An affine substitution does not increase polynomial degree. Therefore phi(F) has a
degree-d certificate.

Applying phi^(-1) gives the reverse implication.

Hence

    d_NS(F) = d_NS(phi(F)).

So **no invertible affine rotation of the Boolean coordinates can reduce the minimum
Nullstellensatz refutation degree.**

The benchmark confirms the theorem numerically: every tested affine basis had zero
successes at degree one below baseline, and the truncated row-space ranks were
invariant.

| case              |   n |   baseline_degree |   target_degree |   rotation_steps |   trials |   successes |   caps |   median_rank |   max_rank |   median_seconds |
|:------------------|----:|------------------:|----------------:|-----------------:|---------:|------------:|-------:|--------------:|-----------:|-----------------:|
| pigeonhole-4x3-d5 |  12 |                 5 |               4 |                4 |       20 |           0 |      0 |           755 |        755 |       0.0218906  |
| pigeonhole-4x3-d5 |  12 |                 5 |               4 |                8 |       20 |           0 |      0 |           755 |        755 |       0.0237811  |
| pigeonhole-4x3-d5 |  12 |                 5 |               4 |               16 |       20 |           0 |      0 |           755 |        755 |       0.0295961  |
| pigeonhole-4x3-d5 |  12 |                 5 |               4 |               32 |       20 |           0 |      0 |           755 |        755 |       0.0406624  |
| random3-n10-d5    |  10 |                 5 |               4 |                4 |       30 |           0 |      0 |           331 |        331 |       0.0159033  |
| random3-n10-d5    |  10 |                 5 |               4 |                8 |       30 |           0 |      0 |           331 |        331 |       0.0169106  |
| random3-n10-d5    |  10 |                 5 |               4 |               16 |       30 |           0 |      0 |           331 |        331 |       0.0243482  |
| random3-n10-d5    |  10 |                 5 |               4 |               32 |       30 |           0 |      0 |           331 |        331 |       0.0362657  |
| random3-n14-d5    |  14 |                 5 |               4 |                4 |       20 |           0 |      0 |           774 |        774 |       0.0803929  |
| random3-n14-d5    |  14 |                 5 |               4 |                8 |       20 |           0 |      0 |           774 |        774 |       0.0883687  |
| random3-n14-d5    |  14 |                 5 |               4 |               16 |       20 |           0 |      0 |           774 |        774 |       0.113301   |
| random3-n14-d5    |  14 |                 5 |               4 |               32 |       20 |           0 |      0 |           774 |        774 |       0.164124   |
| random3-n8-d4     |   8 |                 4 |               3 |                4 |       30 |           0 |      0 |            40 |         40 |       0.00300648 |
| random3-n8-d4     |   8 |                 4 |               3 |                8 |       30 |           0 |      0 |            40 |         40 |       0.00299004 |
| random3-n8-d4     |   8 |                 4 |               3 |               16 |       30 |           0 |      0 |            40 |         40 |       0.00433908 |
| random3-n8-d4     |   8 |                 4 |               3 |               32 |       30 |           0 |      0 |            40 |         40 |       0.00594362 |

This is a significant correction to the earlier RRLS intuition. Linear coordinate
rotation can reveal sparse formulas such as parity, but it cannot lower this particular
algebraic proof-degree invariant.

---

## 5. Nonlinear reversible coordinates

v0.18 next tested exact Toffoli-style Boolean automorphisms

    x_i -> x_i XOR (x_j x_k).

Unlike affine transformations, these can change degree, and the degree-d row-space rank
did change.

Measured:

| case              |   n |   baseline_degree |   target_degree |   trials |   successes |   caps |   min_rank |   median_rank |   max_rank |   total_seconds |
|:------------------|----:|------------------:|----------------:|---------:|------------:|-------:|-----------:|--------------:|-----------:|----------------:|
| pigeonhole-4x3-d5 |  12 |                 5 |               4 |      220 |           0 |      0 |        740 |           742 |        749 |        4.82676  |
| random3-n10-d5    |  10 |                 5 |               4 |      360 |           0 |      0 |        286 |           306 |        321 |        5.92699  |
| random3-n14-d5    |  14 |                 5 |               4 |      220 |           0 |      0 |        621 |           700 |        737 |       18.8444   |
| random3-n8-d4     |   8 |                 4 |               3 |      168 |           0 |      0 |         27 |            33 |         39 |        0.478215 |

No tested single-Toffoli map lowered the minimum refutation degree by one for the four
chosen hard instances.

This is an empirical failure of a small nonlinear transform family, not an
impossibility theorem for nonlinear reversible transformations.

---

## 6. Relation to known algebraic proof complexity

The experiment is now directly in the territory of Polynomial Calculus,
Nullstellensatz, Gröbner-basis algorithms and Ideal Proof System research.

Known results establish high Polynomial Calculus degree for expander-based formula
families and exponential size for functional pigeonhole variants. 2026 work also gives
an unconditional exponential bit-size lower bound for a strong Polynomial Calculus
system augmented with extension variables and a square-root rule on the Binary Value
Principle over Q.

Therefore "lift to monomials and perform rank" and "add arbitrary extension names" are
not universal polynomial solutions by themselves.

---

## 7. What survives from RRLS

The successful RRLS canonicalizers still fit the same pattern:

    XOR         -> linear rank over GF(2)
    2-SAT       -> SCC invariant
    Horn        -> closure invariant
    ALLDIFFERENT-> matching invariant

The important distinction is that these canonicalizers choose a feature space of
polynomial dimension **without searching all features**.

The universal missing link would be an algorithm that takes arbitrary F and computes,
in polynomial time, a polynomial-dimensional feature algebra A_F such that fiber
nonemptiness is decided by polynomial-time operations in A_F.

That would be a real P=NP algorithm.

No such universal feature-algebra canonicalizer is proved here.

---

## 8. Strongest current formulation

Define a canonicalizer

    C(F) -> (basis B_F, operators O_F, invariant I_F)

such that:

1. C runs in polynomial time;
2. |B_F| is polynomial in |F|;
3. operators are exact and polynomial-time;
4. I_F decides whether the solution fiber is empty;
5. recursive composition/projection stays inside polynomial-dimensional bases.

For Polynomial Calculus, B_F is the degree-d monomial basis. The failure mode is that
the required d can grow.

For XOR, B_F is merely the linear coordinate basis and rank is enough.

The remaining challenge is to find a basis family that adapts as powerfully as RRLS
wants without hiding exponential work in basis discovery or basis size.

That is the wall after v0.18.
