feat: D16 adjudication — 2v2 stays hypothesis until a rule fires. (#35)

temporal_freshness then authority_pairing; unresolved keeps (not confirmed).
bin/facts/audit contradict. Gitea #29.

AGENTS.md

@@ -48,7 +48,7 @@ bin/postgres/ query.go (read-only YAML)
 bin/git/      import.go (go-git history; Python shim execs it)
 bin/web/      search.go (SearXNG; Python shim execs it)
 bin/reasoner/ bakeoff.go (D18 CPU OpenAI tool-call bake-off)
-internal/     shared Go (brain/rank is cgo-free; chats parsers; gitlog; websearch; reasoner; duckstats)
+internal/     shared Go (brain/rank is cgo-free; facts D16; chats; gitlog; websearch; reasoner; duckstats)
 bin/qa/       stats.go (DuckDB quantiles / JSONL count; gcc CGO, not Zig)
 bin/watch/    corpus watcher (used by bin/brain/watch.go)
 bin/tools/    vendored python libs behind bin/* (kblib, yamlout, websearch)
@@ -84,7 +84,7 @@ bin/brain/index.go --rebuild --with-facts --with-chats
 ## Tools
 
 ```bash
-bin/facts/audit.go ["self"|"facts"|"info"|"stale"]  # 2-source + staleness gate
+bin/facts/audit.go ["self"|"db"|"contradict"]     # 2-source + D16 adjudication
 bin/facts/crm.go [--dry-run]                       # proof person↔company/company↔project (ooCRM × corpus SoT)
 bin/kb/search "query" [--repo X]                  # deprecated wrapper → bin/brain/search.go
 bin/brain/search.go "query" [--root facts|info]   # deduction search → YAML

PLAN.md

@@ -5,8 +5,10 @@ RAG over the operational Brain/ops/eSlider stack. Built like Sherlock
 Holmes: nothing is asserted unless it has proof.
 
 Status: **v1 in** (epic [#16](https://git.produktor.io/eSlider/2dph/issues/16) closed).
-v2 board: milestone [v2](https://git.produktor.io/eSlider/2dph/milestone/13) — OCR [#6](https://git.produktor.io/eSlider/2dph/issues/6),
-[#29](https://git.produktor.io/eSlider/2dph/issues/29) OQ1, [#30](https://git.produktor.io/eSlider/2dph/issues/30) OQ3.
+v2 board: milestone [v2](https://git.produktor.io/eSlider/2dph/milestone/13) —
+OCR [#6](https://git.produktor.io/eSlider/2dph/issues/6) in,
+[#29](https://git.produktor.io/eSlider/2dph/issues/29) OQ1 in,
+[#30](https://git.produktor.io/eSlider/2dph/issues/30) OQ3 in.
 Gap: [docs/roadmap.md](docs/roadmap.md).
 
 ## What
@@ -42,7 +44,7 @@ detective method: **a fact needs ≥2 independent sources or it is
 | D13 | portfolio | start graph `(Person:eslider)-[:HAS]->(Portfolio)`, associate other natural/juristic persons later. |
 | D14 | tooling style | `bin/{subject}/{method}.go` shebang (e.g. `bin/brain/search.go`). Shared code in `internal/`. One root `go.mod` + `go.work`. No `bin/*/main.go`, no nested modules. |
 | D15 | repo | Gitea [`eSlider/2dph`](https://git.produktor.io/eSlider/2dph) is origin + [issues](https://git.produktor.io/eSlider/2dph/issues). GitHub `eSlider/2dph` is the public clone (PRs + Actions CI). No direct `main` pushes. TDD → PR → CI green → merge. |
-| D16 | contradictions | ≥2 yes vs ≥2 no → unrelated sources conflict → hypothesis → `(not confirmed)`. Resolution (authority, staleness adjudication) = **v2**, tracked as open question. |
+| D16 | contradictions | ≥2 yes vs ≥2 no → hypothesis → `(not confirmed)` until a rule fires. Order: **temporal_freshness** (fresh ≥2 vs stale minority), then **authority_pairing** (runtime/config A×B beats narrative C). Store as `a x b vs c x d` on hypothesis leafs. `bin/facts/audit contradict`. [#29](https://git.produktor.io/eSlider/2dph/issues/29). |
 | D17 | assertion gate | Fact-check every *claim* (facts → info → live → web), not every edit. `bin/brain/search.go` adds a `web` block when there is no facts hit (`throttled`/`skipped`/`refused` ≠ absence). `--root` and `--no-web` stay local. Missing graph ≠ “does not exist”. |
 | D18 | reasoner | Pluggable OpenAI-compatible URL (`REASONER_BASE_URL`). RAM: `Qwen/Qwen3.5-9B`. Quality: `prism-ml/Bonsai-27B-gguf` or `Qwen/Qwen3.6-27B`. No official Qwen3.6-9B. CPU bake-off: `bin/reasoner/bakeoff.go` + compose profile `reasoner` (`OLLAMA_NUM_GPU=0`, `:11435`). PicoClaw is compose profile `picoclaw`; tools are `search`/`get`/`audit`. Weights are not copied into the 2dph image. Agent lever/loop: [#15](https://git.produktor.io/eSlider/2dph/issues/15). |
 | D19 | git history | [go-git](https://github.com/go-git/go-git) via `bin/git/import.go`. No subprocess of the git binary. Conversion prints commit leafs; brain write is `bin/brain/index.go`. |
@@ -117,8 +119,8 @@ Common props on every node/edge: `root`, `confidence`, `evidence[]`, `how`,
 
 ## Open questions (v2)
 
-- OQ1: mutually-contradicting evidence — how to resolve (authority weighting,
-  temporal freshness, audit adjudication). **v2**; [#29](https://git.produktor.io/eSlider/2dph/issues/29).
+- OQ1: **in** — D16 adjudication: `temporal_freshness` then `authority_pairing`.
+  Unresolved 2v2 stays hypothesis. [#29](https://git.produktor.io/eSlider/2dph/issues/29).
 - OQ2: OCR — **in**. `pdftotext -layout` first; scans `pdftoppm` + tesseract
   `eng+deu` (`bin/mail/ocr.go`, `internal/ocr`). No gocv, no gosseract CGO
   (D21 Zig owns Ladybug CGO). Optional `OCR_ENGINE=paddle` / compose profile
@@ -184,4 +186,4 @@ Narrative: [docs/roadmap.md](docs/roadmap.md).
 | 4 | [#15](https://git.produktor.io/eSlider/2dph/issues/15) | **in** — lever/loop documented (`search` → `get` → `audit`). |
 | 5 | [#19](https://git.produktor.io/eSlider/2dph/issues/19) | **in** — CI recall SoT is `bin/brain/eval.go` via Zig. Python `bin/kb/eval` stays as an explicit fallback. |
 
-Does **not** block epic close: OQ1 [#29](https://git.produktor.io/eSlider/2dph/issues/29), OQ3 [#30](https://git.produktor.io/eSlider/2dph/issues/30), OQ4. OCR [#6](https://git.produktor.io/eSlider/2dph/issues/6) is **in**.
+Does **not** block epic close: OQ4. OCR [#6](https://git.produktor.io/eSlider/2dph/issues/6), OQ1 [#29](https://git.produktor.io/eSlider/2dph/issues/29), OQ3 [#30](https://git.produktor.io/eSlider/2dph/issues/30) are **in**.

bin/facts/audit

@@ -1,14 +1,15 @@
 #!/usr/bin/env python3
 """facts/audit - evidence & lexicon checks for the 2dph brain.
 
-  bin/facts/audit self      # lexicon: every fact in db has >=2 sources
-  bin/facts/audit db        # evidence gate: run against var/kb.lbug
+  bin/facts/audit self         # lexicon: docs + two-source rule
+  bin/facts/audit db           # evidence gate against var/kb.lbug
+  bin/facts/audit contradict   # D16 adjudication (JSON claim(s) on stdin)
 
-`self` mode checks the repo itself (no network, no runtime deps). It greps
-for known-good two-source pairings and confirms the docs are consistent.
-`db` mode loads every Leaf with root=facts and asserts each has source_rev
-and a non-empty `loc` (the "where did you see it" evidence pointer) and that
-'confirmed' facts carry a two-source `source` field.
+`self` mode checks the repo itself (no network, no runtime deps).
+`db` mode loads every Leaf with root=facts. Confirmed facts need ` x `;
+hypothesis contradictions need `a x b vs c x d` (both sides ≥2).
+`contradict` applies temporal_freshness then authority_pairing; ≥2 vs ≥2
+with no rule stays hypothesis / `(not confirmed)`.
 
 Exit 0 = all checks pass, 1 = audit failures, 2 = could not evaluate.
 """
@@ -22,6 +23,8 @@ from pathlib import Path
 ROOT = Path(__file__).resolve().parents[2]
 sys.path.insert(0, str(ROOT / "bin" / "tools"))
 
+from contradict import adjudicate, check_fact_row  # noqa: E402
+
 
 def audit_db() -> list[str]:
     from kblib import connect
@@ -33,14 +36,8 @@ def audit_db() -> list[str]:
     r = conn.execute("MATCH (l:Leaf {root:'facts'}) RETURN l.id, l.source, l.loc, l.how, l.confidence")
     problems: list[str] = []
     for lid, source, loc, how, conf in r.get_all():
-        if conf != "confirmed":
-            problems.append(f"{lid}: facts require confidence='confirmed', got '{conf}'")
-        if not source or " x " not in source:
-            problems.append(f"{lid}: needs 2-source evidence in source, got '{source}'")
-        if not loc:
-            problems.append(f"{lid}: missing loc (evidence pointer)")
-        if not how:
-            problems.append(f"{lid}: missing how")
+        problems.extend(check_fact_row(str(lid), str(source or ""), str(loc or ""),
+                                       str(how or ""), str(conf or "")))
     conn.close()
     db.close()
     return problems
@@ -54,20 +51,50 @@ def audit_self() -> list[str]:
         problems.append("PLAN.md missing recall@5 gate")
     if re.search(r"(?i)facts must have.*2 sources|2.source", plan) is None:
         problems.append("PLAN.md missing the two-source evidence rule for facts")
+    if "temporal_freshness" not in plan or "authority_pairing" not in plan:
+        problems.append("PLAN.md missing D16 adjudication rules")
     if re.search(r"(?i)HNSW|BM25|deduction", (ROOT / "README.md").read_text()) is None:
         problems.append("README.md missing search/retrieval description")
     return problems
 
 
+def audit_contradict(raw: str) -> tuple[list[str], list[dict]]:
+    raw = raw.strip()
+    if not raw:
+        return ["contradict: empty stdin (JSON claim or {claims:[...]})"], []
+    try:
+        payload = json.loads(raw)
+    except json.JSONDecodeError as e:
+        return [f"contradict: invalid JSON: {e}"], []
+    if isinstance(payload, dict) and "claims" in payload:
+        claims = list(payload.get("claims") or [])
+    elif isinstance(payload, dict):
+        claims = [payload]
+    elif isinstance(payload, list):
+        claims = payload
+    else:
+        return ["contradict: expected object or list"], []
+    details = [adjudicate(c) for c in claims]
+    return [], details
+
+
 def main(argv: list[str]) -> int:
     import argparse
     p = argparse.ArgumentParser(description="evidence & lexicon audit")
-    p.add_argument("mode", choices=("self", "db"))
+    p.add_argument("mode", choices=("self", "db", "contradict"))
     p.add_argument("--json", action="store_true")
     a = p.parse_args(argv)
 
-    problems = audit_self() if a.mode == "self" else audit_db()
-    out = {"mode": a.mode, "ok": not problems, "problems": problems}
+    details: list[dict] = []
+    if a.mode == "self":
+        problems = audit_self()
+    elif a.mode == "db":
+        problems = audit_db()
+    else:
+        problems, details = audit_contradict(sys.stdin.read())
+    out: dict = {"mode": a.mode, "ok": not problems, "problems": problems}
+    if details:
+        out["contradictions"] = details
     if a.json:
         print(json.dumps(out, indent=2))
     else:

bin/facts/audit.go

@@ -5,6 +5,7 @@
 //
 //	./bin/facts/audit.go self
 //	./bin/facts/audit.go db
+//	./bin/facts/audit.go contradict --json < claim.json
 //
 // Python bin/facts/audit is the implementation (CI runs it directly).
 // NOTE: never run `gofmt -w` on this file — it breaks the shebang.

bin/tools/contradict.py

@@ -0,0 +1,103 @@
+"""D16 contradiction adjudication (same rules as internal/facts)."""
+from __future__ import annotations
+
+from typing import Any
+
+CONF_CONFIRMED = "confirmed"
+CONF_HYPOTHESIS = "hypothesis"
+
+RULE_UNRESOLVED = "unresolved"
+RULE_TEMPORAL = "temporal_freshness"
+RULE_AUTHORITY = "authority_pairing"
+RULE_TWO_SOURCE = "two_source"
+RULE_SINGLE = "single_source"
+
+KIND_RUNTIME = "runtime"
+KIND_CONFIG = "config"
+KIND_NARRATIVE = "narrative"
+
+
+def _independent(sources: list[dict]) -> int:
+    seen: set[str] = set()
+    for i, s in enumerate(sources):
+        sid = str(s.get("id") or "") or f"{s.get('kind', '')}#{i}"
+        seen.add(sid)
+    return len(seen)
+
+
+def _fresh_n(sources: list[dict]) -> int:
+    return sum(1 for s in sources if not s.get("stale"))
+
+
+def _strong_n(sources: list[dict]) -> int:
+    return sum(1 for s in sources if s.get("kind") in (KIND_RUNTIME, KIND_CONFIG))
+
+
+def adjudicate(claim: dict[str, Any]) -> dict[str, Any]:
+    yes = list(claim.get("yes") or [])
+    no = list(claim.get("no") or [])
+    yes_n, no_n = _independent(yes), _independent(no)
+    text = str(claim.get("text") or "")
+
+    def out(conf: str, rule: str, winner: str = "") -> dict[str, Any]:
+        return {
+            "text": text,
+            "confidence": conf,
+            "confirmed": conf == CONF_CONFIRMED,
+            "rule": rule,
+            "winner": winner,
+            "yes": yes_n,
+            "no": no_n,
+        }
+
+    if yes_n < 2 or no_n < 2:
+        if yes_n >= 2:
+            return out(CONF_CONFIRMED, RULE_TWO_SOURCE, "yes")
+        if no_n >= 2:
+            return out(CONF_CONFIRMED, RULE_TWO_SOURCE, "no")
+        return out(CONF_HYPOTHESIS, RULE_SINGLE)
+    yf, nf = _fresh_n(yes), _fresh_n(no)
+    if yf >= 2 and nf < 2:
+        return out(CONF_CONFIRMED, RULE_TEMPORAL, "yes")
+    if nf >= 2 and yf < 2:
+        return out(CONF_CONFIRMED, RULE_TEMPORAL, "no")
+    ys, ns = _strong_n(yes), _strong_n(no)
+    if ys >= 2 and ns < 2:
+        return out(CONF_CONFIRMED, RULE_AUTHORITY, "yes")
+    if ns >= 2 and ys < 2:
+        return out(CONF_CONFIRMED, RULE_AUTHORITY, "no")
+    return out(CONF_HYPOTHESIS, RULE_UNRESOLVED)
+
+
+def parse_source_field(source: str) -> tuple[str, str]:
+    """Split `a x b vs c x d` into (yes, no). Empty no if no ` vs `."""
+    if " vs " not in source:
+        return source, ""
+    yes, _, no = source.partition(" vs ")
+    return yes.strip(), no.strip()
+
+
+def check_fact_row(lid: str, source: str, loc: str, how: str, conf: str) -> list[str]:
+    """Lexicon checks for one facts leaf (no Ladybug)."""
+    problems: list[str] = []
+    src = source or ""
+    if conf == CONF_CONFIRMED:
+        if " vs " in src:
+            problems.append(f"{lid}: confirmed fact cannot keep a vs-contradiction")
+        if " x " not in src:
+            problems.append(f"{lid}: needs 2-source evidence in source, got '{source}'")
+    elif conf == CONF_HYPOTHESIS:
+        yes, no = parse_source_field(src)
+        if not no or " x " not in yes or " x " not in no:
+            problems.append(
+                f"{lid}: hypothesis contradiction needs 'a x b vs c x d', got '{source}'"
+            )
+    elif conf == "partial":
+        pass
+    else:
+        problems.append(f"{lid}: unknown confidence '{conf}'")
+    if not loc:
+        problems.append(f"{lid}: missing loc (evidence pointer)")
+    if not how:
+        problems.append(f"{lid}: missing how")
+    return problems

bin/tools/test_bin_layout.py

@@ -127,6 +127,22 @@ class BinLayoutTest(unittest.TestCase):
             self.assertIn("cmdbin.ExecFile", text)
             self.assertIn(f"bin/facts/{method.removesuffix('.go')}", text)
 
+    def test_d16_adjudication_is_cgo_free(self) -> None:
+        self.assertTrue((ROOT / "internal" / "facts" / "contradict.go").is_file())
+        go = (ROOT / "internal" / "facts" / "contradict.go").read_text()
+        py = (ROOT / "bin" / "tools" / "contradict.py").read_text()
+        audit = (ROOT / "bin" / "facts" / "audit").read_text()
+        for token in ("temporal_freshness", "authority_pairing", "unresolved"):
+            self.assertIn(token, go)
+            self.assertIn(token, py)
+        self.assertIn("contradict", audit)
+        self.assertIn(" vs ", py)
+        plan = (ROOT / "PLAN.md").read_text()
+        self.assertIn("temporal_freshness", plan)
+        self.assertIn("authority_pairing", plan)
+        shebang = (ROOT / "bin" / "facts" / "audit.go").read_text()
+        self.assertIn("contradict", shebang)
+
     def test_mail_import_is_shebang_not_brain_write(self) -> None:
         self._assert_shebang("bin/mail/import.go")
         index_mail = (ROOT / "bin" / "mail" / "index_mail").read_text()

bin/tools/test_contradict.py

@@ -0,0 +1,104 @@
+import os
+import sys
+import unittest
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from contradict import (  # noqa: E402
+    RULE_AUTHORITY,
+    RULE_SINGLE,
+    RULE_TEMPORAL,
+    RULE_TWO_SOURCE,
+    RULE_UNRESOLVED,
+    adjudicate,
+    check_fact_row,
+    parse_source_field,
+)
+
+
+def src(i, kind, stale=False):
+    return {"id": i, "kind": kind, "stale": stale}
+
+
+class TestContradict(unittest.TestCase):
+    def test_two_vs_two_stays_hypothesis(self):
+        r = adjudicate({
+            "text": "svc listens on 443",
+            "yes": [src("docker-ps", "runtime"), src("compose", "config")],
+            "no": [src("docker-old", "runtime"), src("compose-old", "config")],
+        })
+        self.assertFalse(r["confirmed"])
+        self.assertEqual(r["rule"], RULE_UNRESOLVED)
+        self.assertEqual(r["winner"], "")
+
+    def test_temporal_freshness(self):
+        r = adjudicate({
+            "text": "svc listens on 443",
+            "yes": [src("docker-ps", "runtime"), src("compose", "config")],
+            "no": [src("old-readme", "narrative", True), src("old-wiki", "narrative", True)],
+        })
+        self.assertTrue(r["confirmed"])
+        self.assertEqual(r["rule"], RULE_TEMPORAL)
+        self.assertEqual(r["winner"], "yes")
+
+    def test_authority_pairing(self):
+        r = adjudicate({
+            "text": "svc listens on 443",
+            "yes": [src("docker-ps", "runtime"), src("compose", "config")],
+            "no": [src("readme", "narrative"), src("wiki", "narrative")],
+        })
+        self.assertTrue(r["confirmed"])
+        self.assertEqual(r["rule"], RULE_AUTHORITY)
+        self.assertEqual(r["winner"], "yes")
+
+    def test_two_source_and_single(self):
+        two = adjudicate({
+            "text": "arc-1 runs Matrix",
+            "yes": [src("compose", "config"), src("docker-ps", "runtime")],
+        })
+        self.assertTrue(two["confirmed"])
+        self.assertEqual(two["rule"], RULE_TWO_SOURCE)
+        one = adjudicate({"text": "maybe", "yes": [src("readme", "narrative")]})
+        self.assertFalse(one["confirmed"])
+        self.assertEqual(one["rule"], RULE_SINGLE)
+
+    def test_parse_source_field(self):
+        yes, no = parse_source_field("docker ps x compose.yml vs old.md x wiki.md")
+        self.assertIn(" x ", yes)
+        self.assertIn(" x ", no)
+
+    def test_check_fact_row_allows_hypothesis_vs(self):
+        p = check_fact_row(
+            "L1", "a.md x b.md vs c.md x d.md", "var/", "audit", "hypothesis",
+        )
+        self.assertEqual(p, [])
+        p = check_fact_row("L2", "a.md x b.md", "var/", "audit", "confirmed")
+        self.assertEqual(p, [])
+        p = check_fact_row("L3", "a.md x b.md vs c.md x d.md", "var/", "audit", "confirmed")
+        self.assertTrue(any("vs-contradiction" in x for x in p))
+        p = check_fact_row("L4", "only-one.md", "var/", "audit", "hypothesis")
+        self.assertTrue(any("a x b vs" in x for x in p))
+
+    def test_audit_contradict_cli_unresolved(self):
+        import json
+        import subprocess
+        from pathlib import Path
+        root = Path(__file__).resolve().parents[2]
+        payload = json.dumps({
+            "text": "svc 443",
+            "yes": [src("a", "runtime"), src("b", "config")],
+            "no": [src("c", "runtime"), src("d", "config")],
+        })
+        proc = subprocess.run(
+            [sys.executable, str(root / "bin" / "facts" / "audit"), "contradict", "--json"],
+            input=payload, capture_output=True, text=True, check=False,
+        )
+        self.assertEqual(proc.returncode, 0, proc.stderr)
+        out = json.loads(proc.stdout)
+        self.assertTrue(out["ok"])
+        self.assertEqual(out["contradictions"][0]["rule"], RULE_UNRESOLVED)
+        self.assertFalse(out["contradictions"][0]["confirmed"])
+
+
+if __name__ == "__main__":
+    unittest.main()

docs/design.md

@@ -71,7 +71,9 @@ corpus HEAD.
 - C: narrative — READMEs, AGENTS.md, docs
 
 Confirmed = A×B or B×C agreement. Single source = hypothesis + `(not confirmed)`.
-Conflicting pairings (≥2 yes vs ≥2 no) = hypothesis (OQ1 → v2 resolution).
+Conflicting pairings (≥2 yes vs ≥2 no) stay hypothesis until
+`temporal_freshness` or `authority_pairing` fires (`bin/facts/audit contradict`,
+[#29](https://git.produktor.io/eSlider/2dph/issues/29)).
 
 ## Read path
 

docs/roadmap.md

@@ -39,11 +39,11 @@ Epic [#16](https://git.produktor.io/eSlider/2dph/issues/16) closed.
 [#6](https://git.produktor.io/eSlider/2dph/issues/6) OCR — **in**.
 [#30](https://git.produktor.io/eSlider/2dph/issues/30) OQ3 duckdb-go — **in**.
 [#29](https://git.produktor.io/eSlider/2dph/issues/29) OQ1 contradiction
-resolution.
+resolution — **in** (`temporal_freshness`, `authority_pairing`).
 
 ## Blockers
 
-None for epic #16 (closed). Remaining v2: OQ1, OQ4.
+None for epic #16 (closed). Remaining v2: OQ4.
 
 ```
 question
@@ -58,8 +58,8 @@ question
 
 ## Not v1
 
-OQ1 contradiction resolution, OQ4 YAML-first leafs.
-OCR (OQ2) and duckdb-go (OQ3/D22) are in.
+OQ4 YAML-first leafs.
+OCR (OQ2), duckdb-go (OQ3/D22), and D16 adjudication (OQ1) are in.
 
 ## Close epic #16 when
 

internal/brain/rank/escalate.go

@@ -19,20 +19,35 @@ type SecondSourceHit struct {
 
 type WebFn func(query string) SecondSource
 
-// ShouldEscalate is true when the default deduction path has no facts hit.
+// ShouldEscalate is true when the default deduction path has no confirmed
+// facts hit. Hypothesis/partial facts are `(not confirmed)` (D16).
 // `--root facts|info` is a single-root ask: do not mix in the web.
 func ShouldEscalate(hits []Hit, rootFilter string) bool {
 	if rootFilter != "" {
 		return false
 	}
 	for _, h := range hits {
-		if h.Root == "facts" {
+		if ConfirmedFact(h) {
 			return false
 		}
 	}
 	return true
 }
 
+// ConfirmedFact is a facts-root hit that is not hypothesis/partial.
+// Empty confidence is treated as confirmed (legacy leafs).
+func ConfirmedFact(h Hit) bool {
+	if h.Root != "facts" {
+		return false
+	}
+	switch h.Confidence {
+	case "hypothesis", "partial":
+		return false
+	default:
+		return true
+	}
+}
+
 // Deduce returns the second-source block, or nil when web must not run.
 func Deduce(hits []Hit, query, rootFilter string, noWeb bool, web WebFn) *SecondSource {
 	if noWeb || web == nil || !ShouldEscalate(hits, rootFilter) {

internal/brain/rank/escalate_test.go

@@ -14,6 +14,16 @@ func TestShouldEscalateWhenNoFacts(t *testing.T) {
 	}
 }
 
+func TestShouldEscalateWhenHypothesisFacts(t *testing.T) {
+	hyp := Hit{ID: "c", Root: "facts", Confidence: "hypothesis", Source: "a x b vs c x d"}
+	if !ShouldEscalate([]Hit{hyp}, "") {
+		t.Fatal("hypothesis facts are (not confirmed); escalate")
+	}
+	if ConfirmedFact(hyp) {
+		t.Fatal("hypothesis is not confirmed")
+	}
+}
+
 func TestShouldNotEscalateWhenFactsConfirm(t *testing.T) {
 	hits := []Hit{h("f", "facts", "docker ps x compose"), h("i", "info", "docs/a.md")}
 	if ShouldEscalate(hits, "") {

internal/brain/rank/query.go

@@ -3,10 +3,10 @@ package rank
 // BM25 ranks best-first, so the top hits are the *highest* scores; cosine
 // distance ranks best-first ascending. Both mirror kblib.py.
 const FTSStmt = "CALL QUERY_FTS_INDEX('Leaf', 'id', $q) " +
-	"RETURN node.id, node.text, node.root, node.source, score ORDER BY score DESC LIMIT $n"
+	"RETURN node.id, node.text, node.root, node.source, score, node.confidence ORDER BY score DESC LIMIT $n"
 
 const VecStmt = "CALL QUERY_VECTOR_INDEX('Leaf', 'Leaf_vec', $q, $n) " +
-	"RETURN node.id, node.text, node.root, node.source, distance ORDER BY distance LIMIT $n"
+	"RETURN node.id, node.text, node.root, node.source, distance, node.confidence ORDER BY distance LIMIT $n"
 
 // HopStmt is the Cypher walk from a search hit. Depth 1 = File, 2 = Commit, 3 = Person.
 func HopStmt(depth int) string {

internal/brain/rank/rank.go

@@ -16,13 +16,14 @@ type HopNode struct {
 
 // Hit is one search result, mirroring the python script's dict shape.
 type Hit struct {
-	ID      string    `json:"id"`
-	Text    string    `json:"text"`
-	Root    string    `json:"root"`
-	Source  string    `json:"-"`
-	Score   float64   `json:"score"`
-	Snippet string    `json:"snippet,omitempty"`
-	Hops    []HopNode `json:"hops,omitempty"`
+	ID         string    `json:"id"`
+	Text       string    `json:"text"`
+	Root       string    `json:"root"`
+	Confidence string    `json:"confidence,omitempty"`
+	Source     string    `json:"-"`
+	Score      float64   `json:"score"`
+	Snippet    string    `json:"snippet,omitempty"`
+	Hops       []HopNode `json:"hops,omitempty"`
 }
 
 // rrfK dampens the contribution of low ranks; same constant as kblib.py.

internal/brain/rank/rank_test.go

@@ -172,4 +172,7 @@ func TestFTSQueryOrdersByScoreDescending(t *testing.T) {
 	if !strings.Contains(FTSStmt, "ORDER BY score DESC") {
 		t.Fatalf("FTS query must order by score DESC, got:\n%s", FTSStmt)
 	}
+	if !strings.Contains(FTSStmt, "node.confidence") {
+		t.Fatal("FTS must return confidence for D16")
+	}
 }

internal/brain/search.go

@@ -212,7 +212,11 @@ func rowsToHits(res *lbug.QueryResult) ([]Hit, error) {
 		root := fmt.Sprint(vals[2])
 		source := fmt.Sprint(vals[3])
 		score := float64(vals[4].(float64))
-		hits = append(hits, Hit{ID: id, Text: text, Root: root, Source: source, Score: score})
+		conf := ""
+		if len(vals) >= 6 {
+			conf = fmt.Sprint(vals[5])
+		}
+		hits = append(hits, Hit{ID: id, Text: text, Root: root, Source: source, Score: score, Confidence: conf})
 	}
 	return hits, nil
 }
@@ -227,24 +231,26 @@ type jsonOut struct {
 }
 
 type jsonHit struct {
-	ID      string         `json:"id"`
-	Text    string         `json:"text"`
-	Root    string         `json:"root"`
-	Score   float64        `json:"score"`
-	Snippet string         `json:"snippet,omitempty"`
-	Hops    []rank.HopNode `json:"hops,omitempty"`
+	ID         string         `json:"id"`
+	Text       string         `json:"text"`
+	Root       string         `json:"root"`
+	Confidence string         `json:"confidence,omitempty"`
+	Score      float64        `json:"score"`
+	Snippet    string         `json:"snippet,omitempty"`
+	Hops       []rank.HopNode `json:"hops,omitempty"`
 }
 
 func toJSONOut(hits []Hit, query, rootFilter string, web *rank.SecondSource) *jsonOut {
 	out := make([]jsonHit, len(hits))
 	for i, h := range hits {
 		out[i] = jsonHit{
-			ID:      h.ID,
-			Text:    h.Text,
-			Root:    h.Root,
-			Score:   h.Score,
-			Snippet: h.Snippet,
-			Hops:    h.Hops,
+			ID:         h.ID,
+			Text:       h.Text,
+			Root:       h.Root,
+			Confidence: h.Confidence,
+			Score:      h.Score,
+			Snippet:    h.Snippet,
+			Hops:       h.Hops,
 		}
 	}
 	return &jsonOut{
@@ -265,6 +271,9 @@ func resultsToDicts(hits []Hit) []any {
 			{"root", h.Root},
 			{"score", h.Score},
 		}
+		if h.Confidence != "" {
+			d = append(d, KV{"confidence", h.Confidence})
+		}
 		if h.Snippet != "" {
 			d = append(d, KV{"snippet", h.Snippet})
 		}

internal/facts/contradict.go

@@ -0,0 +1,120 @@
+// Package facts is cgo-free evidence rules (D16 contradictions).
+package facts
+
+import "strconv"
+
+const (
+	ConfConfirmed  = "confirmed"
+	ConfHypothesis = "hypothesis"
+
+	RuleUnresolved        = "unresolved"
+	RuleTemporalFreshness = "temporal_freshness"
+	RuleAuthorityPairing  = "authority_pairing"
+	RuleTwoSource         = "two_source"
+	RuleSingleSource      = "single_source"
+
+	KindRuntime   = "runtime"
+	KindConfig    = "config"
+	KindNarrative = "narrative"
+)
+
+// Source is one independent pointer on a yes or no side.
+type Source struct {
+	ID    string `json:"id"`
+	Kind  string `json:"kind"`
+	When  string `json:"when,omitempty"`
+	Stale bool   `json:"stale,omitempty"`
+}
+
+// Claim is one assertion with yes/no evidence lists.
+type Claim struct {
+	Text string   `json:"text"`
+	Yes  []Source `json:"yes"`
+	No   []Source `json:"no"`
+}
+
+// Result is audit output. Confirmed=false means `(not confirmed)`.
+type Result struct {
+	Text       string `json:"text"`
+	Confidence string `json:"confidence"`
+	Confirmed  bool   `json:"confirmed"`
+	Rule       string `json:"rule"`
+	Winner     string `json:"winner,omitempty"`
+	YesN       int    `json:"yes"`
+	NoN        int    `json:"no"`
+}
+
+func independent(ss []Source) int {
+	seen := map[string]struct{}{}
+	for i, s := range ss {
+		id := s.ID
+		if id == "" {
+			id = s.Kind + "#" + strconv.Itoa(i)
+		}
+		seen[id] = struct{}{}
+	}
+	return len(seen)
+}
+
+func freshN(ss []Source) int {
+	n := 0
+	for _, s := range ss {
+		if !s.Stale {
+			n++
+		}
+	}
+	return n
+}
+
+func strongN(ss []Source) int {
+	n := 0
+	for _, s := range ss {
+		if s.Kind == KindRuntime || s.Kind == KindConfig {
+			n++
+		}
+	}
+	return n
+}
+
+func out(c Claim, conf, rule, winner string) Result {
+	return Result{
+		Text:       c.Text,
+		Confidence: conf,
+		Confirmed:  conf == ConfConfirmed,
+		Rule:       rule,
+		Winner:     winner,
+		YesN:       independent(c.Yes),
+		NoN:        independent(c.No),
+	}
+}
+
+// Adjudicate applies D16: ≥2 yes vs ≥2 no stays hypothesis until a rule fires.
+// Order: temporal_freshness, then authority_pairing (A/B beats narrative C).
+func Adjudicate(c Claim) Result {
+	yesN := independent(c.Yes)
+	noN := independent(c.No)
+	if yesN < 2 || noN < 2 {
+		if yesN >= 2 {
+			return out(c, ConfConfirmed, RuleTwoSource, "yes")
+		}
+		if noN >= 2 {
+			return out(c, ConfConfirmed, RuleTwoSource, "no")
+		}
+		return out(c, ConfHypothesis, RuleSingleSource, "")
+	}
+	yf, nf := freshN(c.Yes), freshN(c.No)
+	if yf >= 2 && nf < 2 {
+		return out(c, ConfConfirmed, RuleTemporalFreshness, "yes")
+	}
+	if nf >= 2 && yf < 2 {
+		return out(c, ConfConfirmed, RuleTemporalFreshness, "no")
+	}
+	ys, ns := strongN(c.Yes), strongN(c.No)
+	if ys >= 2 && ns < 2 {
+		return out(c, ConfConfirmed, RuleAuthorityPairing, "yes")
+	}
+	if ns >= 2 && ys < 2 {
+		return out(c, ConfConfirmed, RuleAuthorityPairing, "no")
+	}
+	return out(c, ConfHypothesis, RuleUnresolved, "")
+}

internal/facts/contradict_test.go

@@ -0,0 +1,86 @@
+package facts
+
+import "testing"
+
+func src(id, kind string, stale bool) Source {
+	return Source{ID: id, Kind: kind, Stale: stale}
+}
+
+func TestTwoVsTwoStaysHypothesis(t *testing.T) {
+	c := Claim{
+		Text: "svc listens on 443",
+		Yes: []Source{
+			src("docker-ps", KindRuntime, false),
+			src("compose", KindConfig, false),
+		},
+		No: []Source{
+			src("docker-ps-old", KindRuntime, false),
+			src("compose-old", KindConfig, false),
+		},
+	}
+	r := Adjudicate(c)
+	if r.Confirmed || r.Confidence != ConfHypothesis || r.Rule != RuleUnresolved {
+		t.Fatalf("2v2 must stay (not confirmed): %+v", r)
+	}
+	if r.Winner != "" {
+		t.Fatalf("unresolved must not name a winner: %+v", r)
+	}
+}
+
+func TestTemporalFreshnessResolvesStaleSide(t *testing.T) {
+	c := Claim{
+		Text: "svc listens on 443",
+		Yes: []Source{
+			src("docker-ps", KindRuntime, false),
+			src("compose", KindConfig, false),
+		},
+		No: []Source{
+			src("old-readme", KindNarrative, true),
+			src("old-wiki", KindNarrative, true),
+		},
+	}
+	r := Adjudicate(c)
+	if !r.Confirmed || r.Rule != RuleTemporalFreshness || r.Winner != "yes" {
+		t.Fatalf("fresh yes vs stale no: %+v", r)
+	}
+}
+
+func TestAuthorityPairingBeatsNarrative(t *testing.T) {
+	c := Claim{
+		Text: "svc listens on 443",
+		Yes: []Source{
+			src("docker-ps", KindRuntime, false),
+			src("compose", KindConfig, false),
+		},
+		No: []Source{
+			src("readme", KindNarrative, false),
+			src("wiki", KindNarrative, false),
+		},
+	}
+	r := Adjudicate(c)
+	if !r.Confirmed || r.Rule != RuleAuthorityPairing || r.Winner != "yes" {
+		t.Fatalf("A×B vs C×C: %+v", r)
+	}
+}
+
+func TestTwoSourceYesIsConfirmed(t *testing.T) {
+	c := Claim{
+		Text: "arc-1 runs Matrix",
+		Yes: []Source{
+			src("compose", KindConfig, false),
+			src("docker-ps", KindRuntime, false),
+		},
+	}
+	r := Adjudicate(c)
+	if !r.Confirmed || r.Rule != RuleTwoSource || r.Winner != "yes" {
+		t.Fatalf("%+v", r)
+	}
+}
+
+func TestSingleSourceIsHypothesis(t *testing.T) {
+	c := Claim{Text: "maybe", Yes: []Source{src("readme", KindNarrative, false)}}
+	r := Adjudicate(c)
+	if r.Confirmed || r.Rule != RuleSingleSource {
+		t.Fatalf("%+v", r)
+	}
+}

skills/brain/SKILL.md

@@ -45,6 +45,8 @@ bin/brain/eval.go                                      # recall@5 >= 0.95 gate (
   are not evidence of absence. `--root facts|info` and `--no-web` skip the web.
 - If recall looks wrong, run `bin/brain/eval.go`; it gates control questions and
   should stay at or above 95% recall@5.
+- Contradictions (≥2 yes vs ≥2 no) stay `(not confirmed)` until
+  `bin/facts/audit contradict` fires `temporal_freshness` or `authority_pairing`.
 - Agents: `GET /openapi.json` and `POST /mcp` on `bin/brain/serve.go` (same
   handlers; tool names match paths `search`/`get`/`stats`/`audit`). Generated
   list: [tools.md](tools.md).