Update a decreases clause

1 files changed, 7 insertions, 1 deletions

diff --git a/tests/fstar/betree/BetreeMain.Clauses.fst b/tests/fstar/betree/BetreeMain.Clauses.fst
index b95d4c7e..fcef89ed 100644
--- a/tests/fstar/betree/BetreeMain.Clauses.fst
+++ b/tests/fstar/betree/BetreeMain.Clauses.fst
@@ -130,12 +130,18 @@ let betree_Node_lookup_first_message_for_key_decreases (key : u64)
   (msgs : betree_List_t (u64 & betree_Message_t)) : betree_List_t (u64 & betree_Message_t) =
   msgs
 
+
+let rec list_length (#a : Type0) (ls : betree_List_t a) : nat =
+  match ls with
+  | Betree_List_Cons _ ls -> 1 + list_length ls
+  | Betree_List_Nil -> 0
+
 (** [betree_main::betree::Node::{5}::apply_upserts]: decreases clause *)
 unfold
 let betree_Node_apply_upserts_decreases
   (msgs : betree_List_t (u64 & betree_Message_t)) (prev : option u64)
   (key : u64) : betree_List_t (u64 & betree_Message_t) =
-  msgs
+  list_length msgs
 
 (** [betree_main::betree::Internal::{4}::lookup_in_children]: decreases clause *)
 unfold