diff --git a/contrib/base-revsets.txt b/contrib/base-revsets.txt
--- a/contrib/base-revsets.txt
+++ b/contrib/base-revsets.txt
@@ -47,3 +47,6 @@ parents(20000)
 # The one below is used by rebase
 (children(ancestor(tip~5, tip)) and ::(tip~5))::
 heads(commonancestors(last(head(), 2)))
+heads(-10000:-1)
+roots(-10000:-1)
+only(max(head()), min(head()))