X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke-formulae.git;a=blobdiff_plain;f=merge.tex;h=48e72702c780d17648ffe6ef5d5e5a6b1253fcce;hp=90f5ab2ede0ee1cbc92ccaf41374242f5cb72028;hb=8382189875aa969a251efc900a568a09e7b64c02;hpb=3ac7463b1a5b9e66ccde2ab7f5a16a294812114e

diff --git a/merge.tex b/merge.tex
index 90f5ab2..48e7270 100644
--- a/merge.tex
+++ b/merge.tex
@@ -172,7 +172,8 @@ $F \le C$ so this suffices.
 Consider $D = C$:  Thus $C \in \py, L \in \py$.
 By Tip Own Contents, $L \haspatch \p$ so $L \neq X$,
 therefore we must have $L=Y$, $R=X$.
-By Tip Merge $M = \baseof{L}$ so $M \in \pn$ so
+Conversely $R \not\in \py$
+so by Tip Merge $M = \baseof{L}$.  Thus $M \in \pn$ so
 by Base Acyclic $M \nothaspatch \p$.  By $\merge$, $D \isin C$,
 and $D \le C$.  OK.