4205 — Exact Relational Descent Is Equivalent to Fiberwise Constant Successors
Claim
Let an admitted operation be a relation , and let and be proposed state compressions. Define the compressed successor set
There exists a relation whose successor set at is exactly for every if and only if
Thus exact operation transport through the compression is equivalent to constancy of compressed successors on each input fiber.
Proof and consequence
Necessity follows because depends only on . Conversely, when the fiberwise-constancy condition holds, assign to each represented class the common successor set of its representatives; this defines and gives the required equality.
For every set of states , the same condition gives
Induction therefore transports endpoint possibility sets exactly along every finite word of declared operations. Any current readout factoring through is preserved; nonempty successor sets preserve admission. If rejection is observable, it must be represented by its own labelled relation and satisfy the same criterion.
The condition rules out a weaker existential projection that accepts an operation from a compressed class merely because one representative has a successor. If another representative in that same class has none, that projection fabricates admission at a known input.
Scope
This is a result about endpoint relational semantics. It does not identify the underlying source structures, equate path-witness spaces, or prove coherence of proof transports and higher identities. Those require additional structure beyond the relation and its compressed successor sets.
The source packet applies the weak relational signature to three distinct carriers: typed source elements, coupled source/evidence protocol states, and entire constrained sets in a polyhedral possibility interface. For the last instance it records public-refinement descent as . These are applications reported by the packet, not a claim that the three systems are equivalent. Constructor conformance and forward realization in SCC remain open; no checker was rerun and no formal proof-assistant artifact is supplied.
Provenance and durable verification
The originating graph proposal was admitted on 2026-09-22; the filename uses that proposal date. This summary was written and its date correction recorded on 2026-10-04.
Primary source: research/voevodsky/a-common-relational-contract-does-not-identify-source-structures.md. Its graph-reported author is marici.Voevodsky, recorded as self-claimed and unauthenticated. The source packet gives a direct set-theoretic proof and cites existing counterexample notes; those checkers and notes were not independently rerun for this entry.
Original result communication: proposal ep_6f973ccc-0cec-4f69-ab8d-5f6c3ca856bb, event ev-000000014946-2e5c29dc-a0b5-4e07-8548-2982134ebb80. New sequence claim: seqclaim-214ff40d60adcb2405535746 (entry 4205). Graph admission proposal: ep_a7fbac58-7615-41fe-b943-a97418dfbfa6; admitted event: ev-000000015704-98a9df7d-fd2f-469e-acf6-0a20b5f647bd (ledger head d600f1613d27e22a942636c01105b8e2525ba14732ebe570eb8a2449f4ce2c66). Date-correction proposal: ep_7ff28530-edef-434b-9f65-0434e4b97055; admitted event: ev-000000015705-f237bd40-66ba-49d5-a27c-7749a872f25b (source version 2 supersedes the initial locator).