RESEARCH / Focused target
Containment of the A115809 carryless multiplier condition
RELEASED FOUNDATIONS / PROPOSED CONNECTION
Research connections
All source anchors (1)
- Containment of Binary Carryless Multiplier ConditionsReleased anchor
Problem
The question
OEIS A115809 asks whether the integers satisfying its defining condition are a subset of A115801. In the notation of the source, the exact question is
$$ \forall k\in\mathbb{N},\qquad 17k=C(49,k)\ \Longrightarrow\ 9k=C(25,k). $$
Here $\mathbb{N}$ includes zero and the same $k$ occurs in both sides. The products $17k$ and $9k$ are ordinary natural-number products. The operation $C$ is binary coefficient convolution over $\mathrm{GF}(2)$:
$$ \operatorname{bit}(C(u,k),t)
\left(\sum_{i=0}^{t} \operatorname{bit}(u,i)\operatorname{bit}(k,t-i)\right)\bmod 2. $$
This is the carryless polynomial product described by OEIS A048720, not ordinary multiplication. The source question and operation are recorded at https://oeis.org/A115809.
Motivation
Our foothold
The source asks for containment of two sets of nonnegative integers defined by different ordinary and carryless multiplier pairs. A resolution must cover every natural input, including zero, and preserve the distinction between ordinary products and the coefficient-convolution operation.
Gap
Missing bridges
The A115809 record retains the question “Subset of A115801 ?”. The bounded
source and literature scope in
Library/Digit/oeis2006a115809.md, together with issue
https://github.com/the-omega-institute/trureturing/issues/23260, found no
exact answer in the checked sources or repository declarations. This records
the source-qualified open status; it does not assert exhaustive worldwide
openness or publication priority.
Route
Proposed approach
The proof uses the imported binary convolution definition and its equality with the recursive binary product. A state is either rejecting or a pair $(c,d)$ recording the ordinary multiplication carry and the remaining exclusive-OR mask. Splitting the next input into its low binary digit gives a transition for each of the two digits.
The finite relation of 101 paired states contains the initial pair, has the
required implication at input zero, and is closed under both transitions.
Nat.evenOddRec then transports the implication through the complete binary
expansion of every natural $k$. The initial pair yields exactly the displayed
implication, with no upper bound on $k$.
Falsifier
What would falsify this route
A natural number $k$ satisfying $17k=C(49,k)$ but not $9k=C(25,k)$ would refute the resolution. A mismatch between the stated coefficient convolution and the imported operation, a failed terminal check, or a transition leaving the 101-state relation would also invalidate the route.
Evidence
Evidence to collect
The truth anchor is
D5/S1/Digit/Admissibility/CarrylessSeventeenNineContainment.result.
Its compiled type is the exact all-natural implication above, and its proof
uses the 101-state relation and unbounded binary induction. The frozen
declaration uses only the allowed axiom closure propext,
Classical.choice, and Quot.sound.
The module keeps the checker terminal and result declarations and its
instance header. The typed Reg mirror preserves the source operation and
compiles, while its machine audit remains unresolved as
IE-C050 ClosedTruthReadout, reason unclassified_form, under the linked
exception
https://github.com/the-omega-institute/trureturing/issues/23260#issuecomment-6477454945.
That exception is disclosed evidence, not a validated registration and not a
substitute for the kernel or frozen state.
Triage
Scope assessment
theorem; resolution proved for the one source-authored containment
question stated above. The result preserves the 101-state mechanism, the
terminal and digit-closure checks, and induction over unbounded natural
inputs. It acknowledges the known carryless operation and answers the
A115809 question only in the displayed direction.
No uniform classification of multiplier pairs, converse implication, additional resolution from A115801 or a neighboring sequence, worldwide priority, or completeness claim is included.
ASSUMED-UNVERIFIED
Unverified assumptions
The literature and repository searches are bounded by the scope recorded in the Library note and issue 23260. Exhaustive worldwide openness and priority are unverified. The Reg audit readout remains unresolved under the linked exception. The finite state relation is used only for this exact multiplier pair and does not establish a general carryless classification.