diff --git a/theories/tactics.v b/theories/tactics.v
index 55d308f5019d8a857d1bdd03615c03a31c9548b6..bcdc20f901b07db0fade3db99db23ccc128264f9 100644
--- a/theories/tactics.v
+++ b/theories/tactics.v
@@ -304,18 +304,18 @@ Ltac f_equiv :=
| |- (?R _) (?f _ _ _ _) _ => simple apply (_ : Proper (R _ ==> R _ ==> R _ ==> R _ ==> _) f)
| |- (?R _ _) (?f _ _ _ _) _ => simple apply (_ : Proper (R _ _ ==> R _ _ ==> R _ _ ==> R _ _ ==> _) f)
| |- (?R _ _ _) (?f _ _ _ _) _ => simple apply (_ : Proper (R _ _ _ ==> R _ _ _ R _ _ _ ==> R _ _ _ ==> _) f)
- (* Next, try to infer the relation. Unfortunately, there is an instance
- of Proper for (eq ==> _), which will always be matched. *)
+ (* Next, try to infer the relation. Unfortunately, very often, it will turn
+ the goal into a Leibniz equality so we get stuck. *)
(* TODO: Can we exclude that instance? *)
- (* TODO: If some of the arguments are the same, we could also
- query for "pointwise_relation"'s. But that leads to a combinatorial
- explosion about which arguments are and which are not the same. *)
| |- ?R (?f _) _ => simple apply (_ : Proper (_ ==> R) f)
| |- ?R (?f _ _) _ => simple apply (_ : Proper (_ ==> _ ==> R) f)
| |- ?R (?f _ _ _) _ => simple apply (_ : Proper (_ ==> _ ==> _ ==> R) f)
| |- ?R (?f _ _ _ _) _ => simple apply (_ : Proper (_ ==> _ ==> _ ==> _ ==> R) f)
- (* In case the function symbol differs, but the arguments are the same,
- maybe we have a pointwise_relation in our context. *)
+ (* In case the function symbol differs, but the arguments are the same,
+ maybe we have a pointwise_relation in our context. *)
+ (* TODO: If only some of the arguments are the same, we could also
+ query for "pointwise_relation"'s. But that leads to a combinatorial
+ explosion about which arguments are and which are not the same. *)
| H : pointwise_relation _ ?R ?f ?g |- ?R (?f ?x) (?g ?x) => simple apply H
end;
try simple apply reflexivity.