diff -r 657c517c7dc6 -r 6d2d993fa76e src/ZF/ROOT
--- a/src/ZF/ROOT	Thu Aug 17 14:13:34 2017 +0200
+++ b/src/ZF/ROOT	Thu Aug 17 14:28:01 2017 +0200
@@ -42,6 +42,8 @@
     Kenneth Kunen, Set Theory: An Introduction to Independence Proofs,
     (North-Holland, 1980)
   *}
+  sessions
+    FOL
   theories
     ZF (global)
     ZFC (global)