diff --git a/implementations/rust/oo/src/lib.rs b/implementations/rust/oo/src/lib.rs
index 3e356ff..193b798 100644
--- a/implementations/rust/oo/src/lib.rs
+++ b/implementations/rust/oo/src/lib.rs
@@ -87,7 +87,7 @@ pub fn value<D: Domain, V: Value<D>>(v: &V) -> &dyn Value<D> {
     v
 }
 
-impl<'a, D: Domain> Value<D> for &'a dyn Value<D> {
+impl<'a, D: Domain, V: Value<D> + ?Sized> Value<D> for &'a V {
     fn value_class(&self) -> ValueClass { (*self).value_class() }
     fn as_boolean(&self) -> Option<bool> { (*self).as_boolean() }
     fn as_float(&self) -> Option<f32> { (*self).as_float() }
@@ -301,7 +301,7 @@ impl<D: Domain> Value<D> for Float {
     fn as_double(&self) -> Option<f64> { Some(self.0 as f64) }
 }
 
-impl<'a, D: Domain> Value<D> for &'a str {
+impl<D: Domain> Value<D> for str {
     fn value_class(&self) -> ValueClass { ValueClass::Atomic(AtomClass::String) }
     fn as_string(&self) -> Option<Cow<'_, str>> { Some(Cow::Borrowed(self)) }
 }
@@ -331,16 +331,6 @@ impl<D: Domain, V: Value<D>> Value<D> for [V] {
     }
 }
 
-impl<'v, D: Domain, V: Value<D>> Value<D> for &'v [V] {
-    fn value_class(&self) -> ValueClass { ValueClass::Compound(CompoundClass::Sequence) }
-    fn is_sequence(&self) -> bool { true }
-    fn len(&self) -> Option<usize> { Some((self as &[V]).len()) }
-    fn index(&self, i: usize) -> &dyn Value<D> { &self[i] }
-    fn iter(&self) -> Option<Box<dyn Iterator<Item = &dyn Value<D>> + '_>> {
-        Some(Box::new(self[..].iter().map(value)))
-    }
-}
-
 impl<D: Domain> Value<D> for Set<Box<dyn Value<D>>> {
     fn value_class(&self) -> ValueClass { ValueClass::Compound(CompoundClass::Set) }
     fn is_set(&self) -> bool { true }