Location and Directory

[hcoop/domtool2.git] / src / tycheck.sml

diff --git a/src/tycheck.sml b/src/tycheck.sml
index 6d58e43..152eaf7 100644 (file)
--- a/src/tycheck.sml
+++ b/src/tycheck.sml
@@ -170,6 +170,8 @@ fun predImplies (p1All as (p1, _), p2All as (p2, _)) =
       | (_, CPrefix p2) => predImplies (p1All, p2)
 
       | (CNot p1, CNot p2) => predImplies (p2, p1)
+      | (CRoot, CNot (CConst _, _)) => true
+      | (CConst s1, CNot (CConst s2, _)) => s1 <> s2
 
       | _ => false