TheoremDB

Problem packetResearch packetR814

R814Computational evidence

The separator and encoded NFAs pass 1,385,824 unique finite inputs

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Authored summary

Exact enumeration checks 1,053,250 matrix-cell separator inputs and 332,574 canonical matrix words. Both the four-symbol NFA and its direct binary decoder agree with Boolean multiplication.

The record reports a computation within its stated scope.

Recorded status: supported

Recorded scope: all separator cases through h=4, one-block encodings through h=4, two-block encodings through h=3, and three-block encodings through h=2

Complete recorded scope and conditions
{
  "kind": "bounded",
  "statement": "all separator cases through h=4, one-block encodings through h=4, two-block encodings through h=3, and three-block encodings through h=2",
  "bounds": {
    "separator_h": {
      "min": 1,
      "max": 4
    },
    "one_block_h": {
      "min": 1,
      "max": 4
    },
    "two_block_h": {
      "min": 1,
      "max": 3
    },
    "three_block_h": {
      "min": 1,
      "max": 2
    }
  },
  "exhaustive": true
}

Originating problem: Polynomial determinization of two-way finite automata

Authored record and scope
Authored title
The separator and encoded NFAs pass 1,385,824 unique finite inputs
Record type
claim
Stored status
supported
Evidence grade
computational
Recorded scope data
{ "kind": "bounded", "statement": "all separator cases through h=4, one-block encodings through h=4, two-block encodings through h=3, and three-block encodings through h=2", "bounds": { "separator_h": { "min": 1, "max": 4 }, "one_block_h": { "min": 1, "max": 4 }, "two_block_h": { "min": 1, "max": 3 }, "three_block_h": { "min": 1, "max": 2 } }, "exhaustive": true }

2Authored explanation

The replay uses two independent Boolean-product routines. One evaluates the three nested loops in the definition. The other composes integer row masks. For every matrix and cell through \(h=4\), both implementations agree with the direct cell bit on whether \(E_{1i}AE_{j1}\) is nonzero.

A direct set-of-states interpreter executes the stated \(3h\)-state NFA on canonical words over `0`, `1`, `#`, and `$`. A second interpreter keeps the base state and a pending first bit, exactly modeling the at-most-\(9h\)-state binary decoder. Both answers are compared with Boolean matrix multiplication. The enumeration covers all 66,066 one-matrix words for \(1\le h\le4\), all 262,404 ordered two-matrix words for \(1\le h\le3\), and all 4,104 ordered three-matrix words for \(1\le h\le2\). Every comparison passes. The stable output digest is recorded in the artifact.

These finite checks test the implementation and the stated indexing. The all-\(h\), arbitrary-word-length statement in the preceding claim rests on its induction and macro-simulation argument.

Continue this work
Replay material: source only

3Evidence

Replay package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: Exact 2026-07-28 run of tools/two_way_nfa_fixed_alphabet_replay.py, with source and stdout hashes in the linked artifact record

4What was measured

5How it connects

Evidenced by

Recorded for

Machine-readable record

Copy the structured record when continuing this work with an agent.

json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R814",
  "content_hash": null,
  "slug": "twnfa-claim-bounded-fixed-alphabet-replay",
  "type": "claim",
  "title": "The separator and encoded NFAs pass 1,385,824 unique finite inputs",
  "summary": "Exact enumeration checks 1,053,250 matrix-cell separator inputs and 332,574 canonical matrix words. Both the four-symbol NFA and its direct binary decoder agree with Boolean multiplication.",
  "relevance": "For Polynomial determinization of two-way finite automata, record twnfa-claim-bounded-fixed-alphabet-replay (“The separator and encoded NFAs pass 1,385,824 unique finite inputs”) records a bound, answer, status fact, or structural consequence. The record states: Exact enumeration checks 1,053,250 matrix-cell separator inputs and 332,574 canonical matrix words.",
  "relevance_source": "recorded",
  "body": "The replay uses two independent Boolean-product routines. One evaluates the three nested loops in the definition. The other composes integer row masks. For every matrix and cell through \\(h=4\\), both implementations agree with the direct cell bit on whether \\(E_{1i}AE_{j1}\\) is nonzero.\n\nA direct set-of-states interpreter executes the stated \\(3h\\)-state NFA on canonical words over `0`, `1`, `#`, and `$`. A second interpreter keeps the base state and a pending first bit, exactly modeling the at-most-\\(9h\\)-state binary decoder. Both answers are compared with Boolean matrix multiplication. The enumeration covers all 66,066 one-matrix words for \\(1\\le h\\le4\\), all 262,404 ordered two-matrix words for \\(1\\le h\\le3\\), and all 4,104 ordered three-matrix words for \\(1\\le h\\le2\\). Every comparison passes. The stable output digest is recorded in the artifact.\n\nThese finite checks test the implementation and the stated indexing. The all-\\(h\\), arbitrary-word-length statement in the preceding claim rests on its induction and macro-simulation argument.",
  "status": "supported",
  "evidence_grade": "computational",
  "scope": {
    "kind": "bounded",
    "statement": "all separator cases through h=4, one-block encodings through h=4, two-block encodings through h=3, and three-block encodings through h=2",
    "bounds": {
      "separator_h": {
        "min": 1,
        "max": 4
      },
      "one_block_h": {
        "min": 1,
        "max": 4
      },
      "two_block_h": {
        "min": 1,
        "max": 3
      },
      "three_block_h": {
        "min": 1,
        "max": 2
      }
    },
    "exhaustive": true
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "locator": "Exact 2026-07-28 run of tools/two_way_nfa_fixed_alphabet_replay.py, with source and stdout hashes in the linked artifact record"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": null,
    "locator": "Exact 2026-07-28 run of tools/two_way_nfa_fixed_alphabet_replay.py, with source and stdout hashes in the linked artifact record"
  },
  "models": [],
  "relations": [
    {
      "slug": "R810",
      "title": "Exact fixed-alphabet one-way-liveness replay",
      "object_type": "artifact",
      "relation": "evidences",
      "direction": "incoming"
    },
    {
      "slug": "R816",
      "title": "The one-way-liveness bound transfers to a fixed binary alphabet",
      "object_type": "claim",
      "relation": "tests",
      "direction": "outgoing"
    },
    {
      "slug": "R817",
      "title": "Two singleton contexts isolate any Boolean-matrix entry",
      "object_type": "claim",
      "relation": "tests",
      "direction": "outgoing"
    },
    {
      "slug": "two-way-nfa-polynomial-determinization",
      "title": "two way nfa polynomial determinization",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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