diff -r 221728aeeb7e -r fa8df5a14486 src/direct_product.rs
--- a/src/direct_product.rs	Wed Sep 03 19:55:05 2025 -0500
+++ b/src/direct_product.rs	Wed Sep 03 20:19:41 2025 -0500
@@ -433,29 +433,12 @@
     V: Instance<B, Q>,
 {
     #[inline]
-    fn eval_decompose<'b, R>(
-        self,
-        f: impl FnOnce(Pair<D::Decomposition<'b>, Q::Decomposition<'b>>) -> R,
-    ) -> R
+    fn eval_ref<'b, R>(&'b self, f: impl FnOnce(Pair<D::Reference<'b>, Q::Reference<'b>>) -> R) -> R
     where
         Pair<A, B>: 'b,
         Self: 'b,
     {
-        self.0
-            .eval_decompose(|a| self.1.eval_decompose(|b| f(Pair(a, b))))
-    }
-
-    #[inline]
-    fn eval_ref_decompose<'b, R>(
-        &'b self,
-        f: impl FnOnce(Pair<D::Reference<'b>, Q::Reference<'b>>) -> R,
-    ) -> R
-    where
-        Pair<A, B>: 'b,
-        Self: 'b,
-    {
-        self.0
-            .eval_ref_decompose(|a| self.1.eval_ref_decompose(|b| f(Pair(a, b))))
+        self.0.eval_ref(|a| self.1.eval_ref(|b| f(Pair(a, b))))
     }
 
     #[inline]
@@ -470,6 +453,14 @@
     fn own(self) -> Pair<A::Principal, B::Principal> {
         Pair(self.0.own(), self.1.own())
     }
+
+    #[inline]
+    fn decompose<'b>(self) -> Pair<D::Decomposition<'b>, Q::Decomposition<'b>>
+    where
+        Self: 'b,
+    {
+        Pair(self.0.decompose(), self.1.decompose())
+    }
 }
 
 impl<'a, A, B, U, V, D, Q> Instance<Pair<A, B>, PairDecomposition<D, Q>> for &'a Pair<U, V>
@@ -483,30 +474,12 @@
     &'a U: Instance<A, D>,
     &'a V: Instance<B, Q>,
 {
-    fn eval_decompose<'b, R>(
-        self,
-        f: impl FnOnce(Pair<D::Decomposition<'b>, Q::Decomposition<'b>>) -> R,
-    ) -> R
+    fn eval_ref<'b, R>(&'b self, f: impl FnOnce(Pair<D::Reference<'b>, Q::Reference<'b>>) -> R) -> R
     where
         Pair<A, B>: 'b,
         Self: 'b,
     {
-        self.0.eval_ref_decompose(|a| {
-            self.1
-                .eval_ref_decompose(|b| f(Pair(D::lift(a), Q::lift(b))))
-        })
-    }
-
-    fn eval_ref_decompose<'b, R>(
-        &'b self,
-        f: impl FnOnce(Pair<D::Reference<'b>, Q::Reference<'b>>) -> R,
-    ) -> R
-    where
-        Pair<A, B>: 'b,
-        Self: 'b,
-    {
-        self.0
-            .eval_ref_decompose(|a| self.1.eval_ref_decompose(|b| f(Pair(a, b))))
+        self.0.eval_ref(|a| self.1.eval_ref(|b| f(Pair(a, b))))
     }
 
     #[inline]
@@ -522,6 +495,15 @@
         let Pair(ref u, ref v) = self;
         Pair(u.own(), v.own())
     }
+
+    #[inline]
+    fn decompose<'b>(self) -> Pair<D::Decomposition<'b>, Q::Decomposition<'b>>
+    where
+        Self: 'b,
+    {
+        let Pair(u, v) = self;
+        Pair(u.decompose(), v.decompose())
+    }
 }
 
 impl<A, B, D, Q> DecompositionMut<Pair<A, B>> for PairDecomposition<D, Q>