diff -r c4e394a9c84c -r 402d717bb5c0 src/operator_arithmetic.rs
--- a/src/operator_arithmetic.rs	Mon Sep 01 13:51:03 2025 -0500
+++ b/src/operator_arithmetic.rs	Mon Sep 01 20:55:34 2025 -0500
@@ -42,15 +42,15 @@
     }
 }
 
-impl<'a, T, V, D, F, C> Mapping<D> for Weighted<T, C>
+impl<'a, T, D, F, C> Mapping<D> for Weighted<T, C>
 where
     F: Float,
     D: Space,
-    T: Mapping<D, Codomain = V>,
-    V: Space + ClosedMul<F>,
+    T: Mapping<D>,
+    T::Codomain: ClosedMul<F>,
     C: Constant<Type = F>,
 {
-    type Codomain = V;
+    type Codomain = T::Codomain;
 
     #[inline]
     fn apply<I: Instance<D>>(&self, x: I) -> Self::Codomain {