diff --git a/src/cdomains/affineEquality/sparseImplementation/sparseVector.ml b/src/cdomains/affineEquality/sparseImplementation/sparseVector.ml
index 685fcbd22d..9fffacb57d 100644
--- a/src/cdomains/affineEquality/sparseImplementation/sparseVector.ml
+++ b/src/cdomains/affineEquality/sparseImplementation/sparseVector.ml
@@ -143,7 +143,7 @@ module SparseVector: AbstractVector =
       failwith "TODO"
 
     let map2_with f v v' = 
-      failwith "TODO"
+      failwith "deprecated"
 
     let findi f v = 
       failwith "TODO"
@@ -173,9 +173,14 @@ module SparseVector: AbstractVector =
       {entries = entries'; len = v.len + v'.len}
 
     let exists f v  = 
-      failwith "TODO"
-
-    let rev v = 
+      let c = v.len in
+      let rec exists_aux at f v =
+        match v with
+        | [] -> if at = 0 then false else f A.zero
+        | (xi, xv)::xs -> if f xv then true else exists_aux (at - 1) f xs
+      in (exists_aux c f v.entries)
+
+      let rev v = 
       failwith "TODO"
 
     let rev_with v = 
diff --git a/src/cdomains/affineEquality/vector.ml b/src/cdomains/affineEquality/vector.ml
index a673b820c7..ce7558c05a 100644
--- a/src/cdomains/affineEquality/vector.ml
+++ b/src/cdomains/affineEquality/vector.ml
@@ -18,6 +18,8 @@ sig
 
   val insert_val_at: int -> num ->  t ->  t
 
+  val map_preserve_zero: ((int * num) -> (int * num)) -> t -> t
+  val map2_preserve_zero: ((int * num) -> (int * num) -> (int * num)) -> t ->  t -> t 
   val apply_with_c: (num -> num -> num) -> num ->  t ->  t
 
   val apply_with_c_with: (num -> num -> num) -> num -> t -> unit