diff --git a/docs/re/data/impossibility-scope-sweep.txt b/docs/re/data/impossibility-scope-sweep.txt
new file mode 100644
index 00000000..e8c2b1be
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+++ b/docs/re/data/impossibility-scope-sweep.txt
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+# Are this corpus's negatives about the WORLD or about an INSTRUMENT?
+# 2026-08-31. The sweep I said I owed after fixing one instance by hand.
+#
+# The mission's third classification is "undecodable, WITH REACH". A negative
+# written as a property of the SUBJECT when what was established is a property of
+# the METHOD is the failure that put "an individual SE's audio is not extractable
+# yet" at the head of a page whose own later section had located the waves, and
+# left INDEX quoting it for days. sylpheed-port swept their tree and reported
+# clean; this is mine.
+#
+# TOOL: tools/re-capture/impossibility_scope.py
+#
+################################################################################
+# 🔴 THE TOOL FAILED ITS OWN CONTROL TWICE, and the control is the only reason
+# this sweep means anything. The control is the ONE KNOWN true positive -- the
+# heading I fixed by hand this week.
+#
+#   FAILURE 1: the pattern required a sentence-ending period. HEADINGS DO NOT END
+#   IN PERIODS, and the known instance was a heading. It matched nothing in any
+#   heading in the corpus, so a "clean" report would have been vacuous.
+#
+#   FAILURE 2: with that fixed, the scoring HID it. "yet" was in my list of words
+#   that scope a negative to a method. ⚠️ IT IS NOT ONE. "yet" and "so far" are
+#   temporal HEDGES that name no instrument, no search and no place looked -- and
+#   that is precisely what let "not extractable yet" read as bounded while
+#   claiming a property of the audio. A scope names a METHOD or a PLACE
+#   ("from the file", "by sorting", "from the hash alone").
+#
+# ✅ Control passes now: the known heading is matched and shown.
+#
+################################################################################
+# ✅ RESULT, where it matters most: the two AMPLIFIER files are CLEAN.
+# Every hit in INDEX.md and HANDOFF.md was read. All are legitimate:
+#   * logical facts -- "layers that never touch the same pixel cannot be ordered
+#     wrongly", "95 s apart is impossible";
+#   * the legend's own definition of *measured* ("not on the disc in any form we
+#     found" -- itself scoped);
+#   * claims quoted in order to mark them retracted;
+#   * INDEX 158, which is my own strikethrough of the refuted SE-audio claim.
+#
+# ⚠️ REACH, and it is large: 147 candidate sentences corpus-wide, 130 of which
+# name no scope in the same sentence. I read the INDEX and HANDOFF subset only.
+# The other files are NOT swept, and the regex has a high false-positive rate --
+# "for a directory that no longer exists" is a match. This is a prompt to read,
+# not a defect count, and reading 130 by hand is the cost nobody has paid yet.
diff --git a/tools/re-capture/impossibility_scope.py b/tools/re-capture/impossibility_scope.py
new file mode 100644
index 00000000..342d6474
--- /dev/null
+++ b/tools/re-capture/impossibility_scope.py
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+#!/usr/bin/env python3
+"""Which negatives in this corpus are about the WORLD, and which about an INSTRUMENT?
+
+The mission's third classification is "undecodable, WITH REACH" -- looked here,
+here and here. A negative written as a property of the subject when what was
+established is a property of the method is the failure that put
+"an individual SE's audio is not extractable yet" at the head of a page whose own
+later section located the waves, and left it quoted in INDEX for days
+(data/index-vs-pages-audit.txt).
+
+sylpheed-port swept their own docs for this and came back clean. Mine has not been
+swept. This finds the candidate sentences; ⚠️ IT DOES NOT JUDGE THEM. A negative
+IS allowed to be about the world -- "a 24-bit modulus cannot name an 8-character
+identifier uniquely" is a fact, not a limitation of a tool. Every hit is read.
+
+Scored, so the reading is ordered rather than exhaustive: a sentence that already
+names an instrument, a search, or a reach is very likely fine.
+
+    impossibility_scope.py [--all]
+"""
+import re, sys
+from pathlib import Path
+
+CLAIM = re.compile(
+    r"[^.\n]*\b(?:not (?:extractable|recoverable|available|possible|decodable|knowable)"
+    r"|cannot be (?:\w+ ){0,3}\w+|is impossible|are impossible|no \w+ exists"
+    r"|nowhere on the disc|unrecoverable|not on the disc)\b[^.\n]*(?:\.|$)", re.I)
+# words that SCOPE a negative to a method, a search or a reach
+# ⚠️ "yet" and "so far" were in this list and are NOT scopes -- they are temporal
+# HEDGES that name no instrument, no search and no place looked. That is exactly
+# what made "an individual SE's audio is not extractable yet" read as bounded while
+# claiming a property of the audio, and it is why this tool's own control failed
+# twice before the list was right. A scope names a METHOD or a PLACE.
+SCOPED = ("looked", "searched", "scan", "probe", "reach", "instrument", "harness",
+          "this container", "with the tools", "our reader", "from the file",
+          "from the disc", "from the image", "from the hash", "by sorting",
+          "by counting", "by re-running", "by key list", "attack", "exhaustive",
+          "we could not", "i could not", "could not find", "not found by", "tested")
+
+files = sorted(Path("docs").rglob("*.md"))
+hits = []
+for f in files:
+    if f.name in ("REFUTED.md", "METHOD.md"):
+        continue          # these are ABOUT dead claims; quoting one is not asserting it
+    for n, line in enumerate(f.read_text(errors="replace").splitlines(), 1):
+        for m in CLAIM.finditer(line):
+            s = m.group(0).strip()
+            if len(s) < 30:
+                continue
+            scoped = sum(1 for w in SCOPED if w in s.lower())
+            hits.append((scoped, f, n, s))
+
+hits.sort(key=lambda h: h[0])
+show = hits if "--all" in sys.argv else [h for h in hits if h[0] == 0]
+print(f"{len(hits)} negative claim(s); {sum(1 for h in hits if h[0]==0)} name no "
+      f"instrument, search or reach in the same sentence.\n")
+for scoped, f, n, s in show[:40]:
+    print(f"  {f}:{n}")
+    print(f"      {s[:150]}")
+
+# 🔴 CONTROL, and it must pass before any output above is believed. The one known
+# instance of this defect in this corpus was a HEADING -- "an individual SE's audio
+# is not extractable yet" -- and the first version of this regex required a
+# sentence-ending period, so it matched NOTHING in any heading and would have
+# reported the corpus clean. Run the control after every edit to the pattern.
+KNOWN = "## \u2754 And a new negative: an individual SE's audio is not extractable yet"
+_m = CLAIM.search(KNOWN)
+print("\ncontrol -- the known true positive (a heading, since fixed):")
+if not _m:
+    print("  \U0001F534 CONTROL FAILED: the pattern does not match it. Nothing above means anything.")
+else:
+    _sc = [w for w in SCOPED if w in _m.group(0).lower()]
+    print(f"  matched; scope words {_sc} -> {'HIDDEN by scoring' if _sc else 'shown'}")
+    if _sc:
+        print("  \U0001F534 CONTROL FAILED: scored as scoped, so it would not appear in the default listing.")