diff -r 9738b51d90d7 -r 4f468d35fa29 src/preadjoint_helper.rs
--- a/src/preadjoint_helper.rs	Sun Apr 27 15:03:51 2025 -0500
+++ b/src/preadjoint_helper.rs	Thu Feb 26 11:38:43 2026 -0500
@@ -2,36 +2,42 @@
 Preadjoint construction helper
 */
 
-use std::marker::PhantomData;
+use alg_tools::error::DynResult;
+pub use alg_tools::linops::*;
+use alg_tools::norms::{HasDualExponent, Norm};
 use alg_tools::types::*;
-pub use alg_tools::linops::*;
-use alg_tools::norms::{Norm, HasDualExponent};
+use std::marker::PhantomData;
 
 /// Helper structure for constructing preadjoints of `S` where `S : Linear<X>`.
 /// [`Linear`] needs to be implemented for each instance, but [`Adjointable`]
 /// and [`BoundedLinear`] have blanket implementations.
-#[derive(Clone,Debug)]
-pub struct PreadjointHelper<'a, S : 'a, X> {
-    pub forward_op : &'a S,
-    _domain : PhantomData<X>
+#[derive(Clone, Debug)]
+pub struct PreadjointHelper<'a, S: 'a, X> {
+    pub forward_op: &'a S,
+    _domain: PhantomData<X>,
 }
 
-impl<'a, S : 'a, X> PreadjointHelper<'a, S, X> {
-    pub fn new(forward_op : &'a S) -> Self {
-        PreadjointHelper { forward_op, _domain: PhantomData }
+impl<'a, S: 'a, X> PreadjointHelper<'a, S, X> {
+    pub fn new(forward_op: &'a S) -> Self {
+        PreadjointHelper {
+            forward_op,
+            _domain: PhantomData,
+        }
     }
 }
 
-impl<'a, X, Ypre, S> Adjointable<Ypre, X>
-for PreadjointHelper<'a, S, X>
+impl<'a, X, Ypre, S> Adjointable<Ypre, X> for PreadjointHelper<'a, S, X>
 where
-    X : Space,
-    Ypre : Space,
-    Self : Linear<Ypre>,
-    S : Clone + Linear<X>
+    X: Space,
+    Ypre: Space,
+    Self: Linear<Ypre>,
+    S: Clone + Linear<X>,
 {
     type AdjointCodomain = S::Codomain;
-    type Adjoint<'b> = S where Self : 'b;
+    type Adjoint<'b>
+        = S
+    where
+        Self: 'b;
 
     fn adjoint(&self) -> Self::Adjoint<'_> {
         self.forward_op.clone()
@@ -39,17 +45,18 @@
 }
 
 impl<'a, F, X, Ypre, ExpXpre, ExpYpre, S> BoundedLinear<Ypre, ExpYpre, ExpXpre, F>
-for PreadjointHelper<'a, S, X>
+    for PreadjointHelper<'a, S, X>
 where
-    ExpXpre : HasDualExponent,
-    ExpYpre : HasDualExponent,
-    F : Float,
-    X : Space + Norm<F, ExpXpre::DualExp>,
-    Ypre : Space + Norm<F, ExpYpre>,
-    Self : Linear<Ypre>,
-    S : 'a + Clone + BoundedLinear<X, ExpXpre::DualExp, ExpYpre::DualExp, F>
+    ExpXpre: HasDualExponent,
+    ExpYpre: HasDualExponent,
+    F: Float,
+    X: Space + Norm<ExpXpre::DualExp, F>,
+    Ypre: Space + Norm<ExpYpre, F>,
+    Self: Linear<Ypre>,
+    S: 'a + Clone + BoundedLinear<X, ExpXpre::DualExp, ExpYpre::DualExp, F>,
 {
-    fn opnorm_bound(&self, expy : ExpYpre, expx : ExpXpre) -> F {
-        self.forward_op.opnorm_bound(expx.dual_exponent(), expy.dual_exponent())
+    fn opnorm_bound(&self, expy: ExpYpre, expx: ExpXpre) -> DynResult<F> {
+        self.forward_op
+            .opnorm_bound(expx.dual_exponent(), expy.dual_exponent())
     }
 }