Divisor-child ancestry theorem for Type A/B shadowing

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Ancestry

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Status: proved universal theorem with coordinator-reviewed q=13 and q=17 classifications

Date: 2026-08-14

Project: Free Computation Foundation / CENTL

Coordinator: Operator-01 / primary research lead

Operator-02 provenance: operator-02/ANCESTRY-Q13-CLASSIFICATION.md, operator-02/ANCESTRY-Q17-CLASSIFICATION.md

Claim boundary: this note concerns unrestricted Type A/B trap-set shadowing along modulus ancestry. It does not prove universal Direct-Shadow Completeness, López Type A/B coverage, or the Erdős-Straus conjecture. Hard-class-conditioned shadowing can be stronger than unrestricted shadowing.

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1. General ancestry parameter

Fix positive integers j and s, and put

Q=4s+1, \qquad K=Qj-s.

Then

4K-1 =Q(4j-1).

Write

m=4j-1.

Thus j -> K is a modulus-divisibility ancestry edge with quotient Q.

The elementary identity

\boxed{K=s m+j}

gives

K\equiv j\pmod m

and

\gcd(j,K)=\gcd(j,s).

Define the normalized ancestor trap set

S_j=-T_j =\{e,4e\pmod m:e\mid j\}.

As in the existing ancestry theory,

T_K\bmod m\subseteq T_j

is equivalent to requiring every divisor of K, reduced modulo m, to lie in S_j.

2. Divisor-child theorem

Theorem

Let

a\mid\gcd(j,s)

and suppose

\boxed{K=a p}

for a prime p.

Then

\boxed{T_K\bmod(4j-1)\subseteq T_j.}

In words:

whenever the child depth is a prime multiplied by a divisor common to the ancestry shift s and the ancestor depth j, the entire child Type A/B trap set is shadowed by the ancestor.

Proof

Write

j=a d, \qquad s=a c.

Then

p=\frac Ka =\frac{(4s+1)j-s}{a}.

Subtract d=j/a:

\begin{aligned} p-d &=4sd-c\\ &=c(4ad-1)\\ &=c(4j-1)\\ &=c m. \end{aligned}

Hence

\boxed{p\equiv d=j/a\pmod m.}

Every divisor E of K=a p can be written in one of the forms

E=b \quad\text{or}\quad E=bp

for some divisor b|a. This remains true if p|a: divisors with the final extra p-exponent use the second form.

If E=b, then

b\mid a\mid j,

so E is an ancestor divisor and lies in S_j.

If E=bp, then

E\equiv b\frac ja\pmod m.

But

b\frac ja =\frac{j}{a/b}

is again a divisor of j. Therefore E mod m lies in S_j.

Thus every divisor of K maps into S_j, proving

T_K\bmod m\subseteq T_j.

QED.

3. Prime-child theorem as the first case

Taking

a=1

recovers the existing prime-child theorem immediately:

K\text{ prime} \Longrightarrow T_K\bmod m\subseteq T_j.

So prime children are the a=1 edge of a larger divisor-child family.

4. Immediate ancestry ladder

For a fixed ancestry shift s, every divisor

a\mid s

that also divides j supplies a potential fully shadowed child shape

\boxed{K=a p,\quad p\text{ prime}.}

This predicts the exact composite families independently observed at the first ancestry quotients.

Q = 5

Here s=1, so only a=1 exists:

K=p.

This agrees with the proved q=5 rigidity theorem: unrestricted full shadow occurs only for prime children.

Q = 9

Here s=2, so

a\in\{1,2\}.

The theorem gives

K=p\quad\text{or}\quad K=2p.

The existing exact classification adds one exceptional smooth child

(j,K)=(2,16).

Q = 13

Here s=3, so

a\in\{1,3\}.

The theorem gives

K=p\quad\text{or}\quad K=3p.

Operator-02 independently proved that these are not merely sufficient but exhaustive.

Q = 17

Here s=4, so

a\in\{1,2,4\}.

The theorem gives

K=p,\quad2p,\quad4p.

Operator-02 independently proved the full converse, with one exceptional smooth child

(j,K)=(4,64).

5. Coordinator review: q = 13 classification

Operator-02 source:

operator-02/ANCESTRY-Q13-CLASSIFICATION.md

Accepted theorem

Let

K=13j-3.

Then

\boxed{ T_K\bmod(4j-1)\subseteq T_j \iff K\text{ is prime or }K=3p\text{ with }p\text{ prime}. }

The direct implication is now subsumed by the divisor-child theorem with s=3.

The Operator-02 converse was reviewed by the Coordinator. Its case split is sound:

  1. if j is odd and K composite, divisor 2 escapes S_j;
  2. if j is even and 3∤j, a least prime factor of composite K is <m, does not divide j, and escapes S_j;
  3. if j=3d, write K=3(13d-1); when the cofactor is composite, a least non-3 prime factor escapes, while the remaining 3-divisible subcase gives divisor 9, and 9∉S_j because 9∤j.

No coarse signature/exact-trap equivalence is used.

Coordinator classification: PROVED / promoted.

6. Coordinator review: q = 17 classification

Operator-02 source:

operator-02/ANCESTRY-Q17-CLASSIFICATION.md

Accepted theorem

Let

K=17j-4.

Then

\boxed{ T_K\bmod(4j-1)\subseteq T_j \iff \begin{cases} K\text{ prime},\text{ or}\\ K=2p,\text{ or}\\ K=4p,\text{ or}\\ (j,K)=(4,64), \end{cases} }

where p is an odd prime in the composite prime-times-divisor cases.

The direct prime/2p/4p implications follow from the divisor-child theorem with s=4.

The Coordinator reviewed the converse by 2-adic cases:

  • odd j: a least prime factor of composite K escapes;
  • v2(K)=1: after j=2d, a least prime factor of the odd composite cofactor escapes;
  • v2(K)=2: same after j=4d;
  • v2(K)=3 or 4: the odd cofactor lies strictly between j and m and hence cannot be in S_j;
  • v2(K)>=5: j≡4 mod8, so v2(j)=2; divisor 32 escapes except at j=4, where K=64 and the power-of-two residues are explicitly contained in S_4.

Coordinator classification: PROVED / promoted.

7. New structural conjecture: prime-times-common-divisor plus smooth exceptions

The first four exact ancestry quotients now have a common form:

\boxed{ \text{full shadow child} = \text{prime}\times a,\quad a\mid\gcd(j,s), }

plus rare children whose entire factorization is supported on the small primes of the shift s.

This motivates the following theorem candidate.

Ancestry converse candidate

For fixed s and sufficiently large j, if

T_{(4s+1)j-s}\bmod(4j-1)\subseteq T_j,

then

\boxed{K=a p}

for some

a\mid\gcd(j,s)

and prime p, except possibly for a finite set of s-smooth children.

This is not proved in general.

8. Why a general converse is plausible

Let ell|K be a prime not dividing j.

If

1<\ell<m=4j-1,

then ell cannot lie in S_j:

  • it is not a plain divisor of j;
  • as a prime it cannot equal 4e for a proper divisor e|j;
  • the endpoint 4j reduces to 1, not ell.

Thus under full shadowing, every prime factor of K below m must divide j, and hence must divide

\gcd(j,K)=\gcd(j,s).

Any prime factor not supported by the shift must therefore be at least m.

Since

K=(4s+1)j-s

grows linearly in j while m^2 grows quadratically, for fixed s and large j one has

K<m^2.

Consequently there can be at most one prime factor outside the shift support.

This is the mechanism behind the observed prime-times-common-divisor families. The remaining work is to control excessive powers of the shift primes and classify the finite smooth exceptions.

9. Proof target

The next ancestry theorem should formalize Section 8 into:

  1. an explicit threshold J(s) above which K<m^2;
  2. a bound on the exponents of primes dividing gcd(j,s) under full shadowing;
  3. a finite classification of s-smooth exceptions below that threshold or with exceptional exponent cycles;
  4. a general converse yielding the divisor-child family as the complete asymptotic ancestry skeleton.

If successful, the separate q=5,9,13,17,... rigidity calculations collapse into one theorem.

That would turn the ancestry portion of the shadow graph from a collection of observed quotient families into a single structural law.