diff --git a/lib/Quox/Equal.idr b/lib/Quox/Equal.idr
index 789b49c..5998b3d 100644
--- a/lib/Quox/Equal.idr
+++ b/lib/Quox/Equal.idr
@@ -916,7 +916,8 @@ parameters (loc : Loc) (ctx : TyContext d n)
                  (EqContext n -> DSubst d 0 -> Eff fs ()) -> Eff fs ()
     eachCorner loc fvs act = do
       say "equal" 50 loc $
-        hsep $ "eachCorner: split on" :: map prettyBind' (getVars ctx fvs)
+        let vars = map prettyBind' (getVars ctx fvs) in
+        hsep $ "eachCorner: split on" :: if null vars then ["(none)"] else vars
       for_ (splits loc ctx.dctx fvs) $ \th =>
         act (makeEqContext ctx th) th