2 files changed, 10 insertions, 0 deletions
diff --git a/src/lem_interp/interp.lem b/src/lem_interp/interp.lem
index 6396f51e..1a97f5db 100644
--- a/src/lem_interp/interp.lem
+++ b/src/lem_interp/interp.lem
@@ -463,6 +463,8 @@ let access_vector v n =
   retaint v (match (detaint v) with
     | V_unknown -> V_unknown 
     | V_lit (L_aux L_undef _) -> v
+    | V_lit (L_aux L_zero _) -> v
+    | V_lit (L_aux L_one _ ) -> v
     | V_vector m dir vs -> 
       list_nth vs (if is_inc(dir) then (n - m) else (m - n))
     | V_vector_sparse _ _ _ vs d ->
diff --git a/src/lem_interp/interp_interface.lem b/src/lem_interp/interp_interface.lem
index baa20ada..e0c656eb 100644
--- a/src/lem_interp/interp_interface.lem
+++ b/src/lem_interp/interp_interface.lem
@@ -135,6 +135,14 @@ instance (Ord address)
   let (>=) a1 a2 = (addressCompare a1 a2) <> LT
 end
 
+let addressEqual a1 a2 = (addressCompare a1 a2) = EQ
+
+instance  (Eq address)
+  let (=) = addressEqual
+  let (<>) x y = not (addressEqual x y)
+end
+
+
 instance (Ord register_value)
   let compare = defaultCompare
   let (<) = defaultLess