X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=invariants.tex;h=ac0558a82bd9fd202ba0e308d543801eba8a1b4c;hb=HEAD;hp=bb926ea1f71460e1db981d110bf06078ab818a78;hpb=54e1d86039f0cb0e7db9e2e7be3f56a611a247f6;p=topbloke-formulae.git

diff --git a/invariants.tex b/invariants.tex
index bb926ea..ac0558a 100644
--- a/invariants.tex
+++ b/invariants.tex
@@ -24,10 +24,15 @@ We maintain these each time we construct a new commit. \\
 \[\eqn{Foreign Inclusion}{
   \bigforall_{D \in \foreign} D \isin C \equiv D \leq C
 }\]
-\[\eqn{Foreign Contents}{
+\[\eqn{Foreign Ancestry}{
   \bigforall_{C \in \foreign}
     D \le C \implies \isforeign{D}
 }\]
+\[\eqn{Bases' Children}{
+  C \hasparent D \land D \in \pdn
+    \implies
+  C \in \pdn \lor C \in \pdy
+}\]
 
 We also assign each new commit $C$ to zero or one of the sets $\p$, as
 stated in the definition of $\patchof{C}$ in the summary for each kind