lean artifact · pending
Artifact ↗Source authenticated
Medvedev logic is undecidable
The paper reduces periodic plane tiling to non-theoremhood in Medvedev logic and proves is undecidable and not recursively axiomatizable. A modification also proves undecidability of Skvortsov logic for infinite problems, and shows the two logics can be separated using any aperiodic plane tiling. Both papers are preprints, so the result should remain a review-pending candidate.
Exact FrontierDelta
Prior state unknown→proved
Scope and record
Occurred: Sep 11, 2026
Delta type: SOURCE CLAIM
Assumptions: VibeMathed verification: lean-checked. Publication: preprint. AI contribution: ai-discovered. VibeMathed editorial classifications, scores, notes, relations, and dataset structure are CC BY 4.0. Source statements and linked content retain their own rights.
Canonical aliases: Medvedev logic is undecidable · Undecidability of Medvedev logic
Confidence: Not scored
Registry verification: lean checked · preprint · candidate
Attribution
VibeMathed
registry · event recorded by
ChatGPT Sol 5.6
model · ai model contributor · OpenAI
Claude Opus 5
model · ai model contributor · Anthropic
Rodrigo Nicolau Almeida
human · human collaborator
Søren Brinck Knudstorp; Pawel Pawlowski
human · human collaborator
Artifacts and verifiers
Compute record
No linked compute attempts recorded.
Lineage and corrections
The paper reduces periodic plane tiling to non-theoremhood in Medvedev logic and proves is undecidable and not recursively axiomatizable. A modification also proves undecidability of Skvortsov logic for infinite problems, and shows the two logics can be separated using any aperiodic plane tiling. Both papers are preprints, so the result should remain a review-pending candidate. parent of this event
This event attributed to Claude Opus 5
Medvedev logic is undecidable evidence for this event
VibeMathed record: Medvedev logic is undecidable evidence for this event
This event attributed to ChatGPT Sol 5.6
Independent near-simultaneous result evidence for this event
Maksimova et al 1979 (in Russian) - Problem statement evidence for this event
This event attributed to Søren Brinck Knudstorp; Pawel Pawlowski
Medvedev logic is undecidable parent of this event
Pawlowski's Lean formalization of the proof evidence for this event
This event attributed to Rodrigo Nicolau Almeida
Act on this frontier