--- a/src/kernels/hat.rs	Thu Jan 23 23:35:28 2025 +0100
+++ b/src/kernels/hat.rs	Mon Jan 06 21:37:03 2025 -0500
@@ -1,7 +1,7 @@
 //! Implementation of the hat function
 
 use numeric_literals::replace_float_literals;
-use serde::Serialize;
+use serde::{Serialize, Deserialize};
 use alg_tools::types::*;
 use alg_tools::norms::*;
 use alg_tools::loc::Loc;
@@ -19,7 +19,7 @@
 use crate::types::Lipschitz;
 
 /// Representation of the hat function $f(x)=1-\\|x\\|\_1/ε$ of `width` $ε$ on $ℝ^N$.
-#[derive(Copy,Clone,Serialize,Debug,Eq,PartialEq)]
+#[derive(Copy,Clone,Serialize,Deserialize,Debug,Eq,PartialEq)]
 pub struct Hat<C : Constant, const N : usize> {
     /// The parameter $ε>0$.
     pub width : C,