diff --git a/src/mm-formal.adoc b/src/mm-formal.adoc
index 58e35ee13..5d2e3d86f 100644
--- a/src/mm-formal.adoc
+++ b/src/mm-formal.adoc
@@ -243,7 +243,7 @@ pred restrict_to_current_encodings {
 // =Alloy shortcuts=
 pred acyclic[rel: Event->Event] { no iden & ^rel }
 pred total[rel: Event->Event, bag: Event] {
-  all disj e, e': bag | e->e' in rel + ~rel
+  all disj e, f: bag | e->f in rel + ~rel
   acyclic[rel]
 }
 ....