{
  "schema_version": 1,
  "series_id": "fixed-mathematics-problem-cohorts",
  "cohort_id": "erdos-problems-1-100",
  "freeze_date": "2026-08-19",
  "source_commit": "881735e82124ab8ad7adea9b7d0aeb3c026dcb95",
  "source_sha256": "69719796f01fbe3a33913d14d1307502fa4361a307fa8e4674d20163a745eb0c",
  "retrieved_at": "2026-08-19",
  "cohort_size": 100,
  "baseline": {
    "at_risk": 54,
    "resolved_before_freeze": 46,
    "verified_resolutions_after_freeze": 0,
    "prize_problems": 40,
    "statement_formalized": 69,
    "formal_solutions": 15
  },
  "informal_status_counts": {
    "decidable": 1,
    "disproved": 12,
    "falsifiable": 3,
    "open": 49,
    "proved": 31,
    "solved": 3,
    "verifiable": 1
  },
  "derived_status_counts": {
    "decidable": 1,
    "disproved": 7,
    "disproved (Lean)": 5,
    "falsifiable": 3,
    "open": 49,
    "proved": 22,
    "proved (Lean)": 9,
    "solved": 2,
    "solved (Lean)": 1,
    "verifiable": 1
  },
  "top_tags": [
    {
      "tag": "number theory",
      "problems": 53
    },
    {
      "tag": "graph theory",
      "problems": 31
    },
    {
      "tag": "additive combinatorics",
      "problems": 13
    },
    {
      "tag": "additive basis",
      "problems": 12
    },
    {
      "tag": "distances",
      "problems": 12
    },
    {
      "tag": "geometry",
      "problems": 12
    },
    {
      "tag": "ramsey theory",
      "problems": 12
    },
    {
      "tag": "cycles",
      "problems": 10
    },
    {
      "tag": "primes",
      "problems": 9
    },
    {
      "tag": "sidon sets",
      "problems": 7
    },
    {
      "tag": "chromatic number",
      "problems": 6
    },
    {
      "tag": "convex",
      "problems": 5
    },
    {
      "tag": "covering systems",
      "problems": 4
    },
    {
      "tag": "combinatorics",
      "problems": 3
    },
    {
      "tag": "unit fractions",
      "problems": 3
    }
  ],
  "catalogue_last_update_range": {
    "earliest": "2025-02-17",
    "latest": "2026-06-07",
    "interpretation": "Catalogue maintenance range only; not a historical discovery timeline."
  },
  "candidate_changes": 0,
  "causal_status": "causality_unresolved",
  "interpretation": "This is a frozen prospective denominator and current-state baseline. It does not estimate historical acceleration or an AI effect."
}