diff -r 86e0228f38f8 -r ff4656da04af src/manifold.rs
--- a/src/manifold.rs	Fri Oct 18 13:51:51 2024 -0500
+++ b/src/manifold.rs	Fri Oct 18 14:22:45 2024 -0500
@@ -2,7 +2,7 @@
 /// A point on a manifold
 pub trait ManifoldPoint : Clone + PartialEq {
     // Type of tangent factors
-    type Tangent;
+    type Tangent : Euclidean<f64, Output=Self::Tangent> + std::fmt::Debug;
 
     /// Exponential map
     fn exp(&self, tangent : &Self::Tangent) -> Self;