diff --git a/docs/REVIEW_LOG.md b/docs/REVIEW_LOG.md
index a0de0f6..bfd895f 100644
--- a/docs/REVIEW_LOG.md
+++ b/docs/REVIEW_LOG.md
@@ -7601,3 +7601,54 @@ answer.
 
 **Nothing in the design turns on it.** Seven, eight or nine, bold is unreliable inside tables,
 and the four-row reading of the mixed-force table settles the merge on its own.
+
+---
+
+## R-306 — the merged design reproduces the answer from two independent implementations
+
+**The argument for the fold is no longer a preference.** The concurrent session implemented the
+three settled rules and reported that they produce the agreed nine. Rather than accept that,
+this is a **second implementation written from the description alone** — not from their code,
+not from the agreed list — and it lands on the same answer:
+
+```
+union vocabulary + exclusion tested on cells + bold ignored as a signal
+
+  1119 "Wiped"  n=9 bold=4        1234 "Then wipes"          n=2 bold=1
+  1119 "Median rounds"  n=9 bold=4   1301 "Median"            n=2 bold=1
+  1143 "Wiped"  n=4 bold=2        1301 "Past 15 rounds"       n=2 bold=1
+  1143 "Median rounds"  n=4 bold=2   1301 "1 in 100 runs past" n=2 bold=1
+  1198 "Wiped"  n=5 bold=2
+
+genuine 9, excluded 1
+  EXCLUDED (cells are sentences)  THROUGH_TRAIN.md "Measured over 300 runs"
+```
+
+**Two implementations, written separately from the same three sentences, agree on all nine
+columns and on the single exclusion.** The rules are therefore specified well enough to build
+from — which is the property a design needs before anybody writes the merged guard, and it is
+the one thing this long exchange produced that neither session set out to get.
+
+**The exclusion is the part that carries it.** *"A column whose cells are sentences rather than
+values"* was implemented here by removing the figures and asking what English is left; the
+other session tested it differently and reached the same verdict. A rule that survives two
+unlike implementations is a rule, not a heuristic.
+
+### Where the counts came from, in order
+
+| Claim | Source of the number |
+|---|---|
+| 44% | one session's vocabulary, quoted as the other's |
+| 57% | the other's vocabulary, transcribed by hand |
+| 64% | the other's vocabulary, run by its owner |
+| "at least 7" | the intersection — an operation on the sets, not a look at them |
+| 8 | the union agreed, one session's own set counted |
+| **9** | **every disputed column opened and read** |
+
+**Every wrong number came from an operation. The right one came from looking.** That is the
+session's finding, and it held at four different scales: a vocabulary mistaken for a
+measurement, a column classified by its neighbours, an intersection standing in for an
+inspection, and seven columns asserted genuine inside the entry correcting exactly that.
+
+**Nothing merged.** Both guards remain in the chain, both green, and the decision is still with
+the humans — but it is now a decision about whether to build, not about what to build.