diff --git a/src/ndim/nmat.rs b/src/ndim/nmat.rs
index 34d37b5a..51b7317b 100644
--- a/src/ndim/nmat.rs
+++ b/src/ndim/nmat.rs
@@ -134,8 +134,7 @@ LMul<NVec<D, T>> for NMat<D, T>
 
 impl<D: Dim,
      T: Clone + Copy + Eq + One + Zero +
-        Mul<T, T> + Quot<T, T> + Sub<T, T> + Neg<T>
-     >
+        Mul<T, T> + Quot<T, T> + Sub<T, T> + Neg<T>>
 Inv for NMat<D, T>
 {
   fn inverse(&self) -> NMat<D, T>
@@ -161,7 +160,7 @@ Inv for NMat<D, T>
       // instead?
 
       // FIXME: this is kind of uggly…
-      // … but we cannot use position_betwee since we are iterating on one
+      // … but we cannot use position_between since we are iterating on one
       // columns
       let mut n0 = 0u; // index of a non-zero entry
 
diff --git a/src/traits/cross.rs b/src/traits/cross.rs
index cf17a324..87fafae2 100644
--- a/src/traits/cross.rs
+++ b/src/traits/cross.rs
@@ -1,4 +1,5 @@
 pub trait Cross<Result>
 {
+  /// Computes the cross product between two elements (usually vectors).
   fn cross(&self, other : &Self) -> Result;
 }
diff --git a/src/traits/dim.rs b/src/traits/dim.rs
index 00364f34..fd91c070 100644
--- a/src/traits/dim.rs
+++ b/src/traits/dim.rs
@@ -1,14 +1,25 @@
 pub trait Dim
 {
+  /// The dimension of the object.
   fn dim() -> uint;
 }
 
 // Some dimension token. Useful to restrict the dimension of n-dimensional
 // object at the type-level.
+/// Dimensional token for 0-dimensions. Dimensional tokens are the preferred
+/// way to specify at the type level the dimension of n-dimensional objects.
 pub struct d0;
+/// Dimensional token for 1-dimension. Dimensional tokens are the preferred
+/// way to specify at the type level the dimension of n-dimensional objects.
 pub struct d1;
+/// Dimensional token for 2-dimensions. Dimensional tokens are the preferred
+/// way to specify at the type level the dimension of n-dimensional objects.
 pub struct d2;
+/// Dimensional token for 3-dimensions. Dimensional tokens are the preferred
+/// way to specify at the type level the dimension of n-dimensional objects.
 pub struct d3;
+/// Dimensional token for 4-dimensions. Dimensional tokens are the preferred
+/// way to specify at the type level the dimension of n-dimensional objects.
 pub struct d4;
 
 impl Dim for d0
diff --git a/src/traits/dot.rs b/src/traits/dot.rs
index 4d57eeff..ead40d7f 100644
--- a/src/traits/dot.rs
+++ b/src/traits/dot.rs
@@ -1,6 +1,14 @@
 pub trait Dot<T>
 {
+  /// Computes the dot (inner) product of two objects.
   fn dot(&self, &Self) -> T;
+  /// Computes the norm a an object.
   fn norm(&self)       -> T;
+  /**
+   * Computes the squared norm of an object.
+   * 
+   * Computes the squared norm of an object. Computation of the squared norm
+   * is usually faster than the norm itself.
+   */
   fn sqnorm(&self)     -> T; // { self.dot(self); }
 }
diff --git a/src/traits/inv.rs b/src/traits/inv.rs
index ac995c77..4b5dc283 100644
--- a/src/traits/inv.rs
+++ b/src/traits/inv.rs
@@ -1,5 +1,7 @@
 pub trait Inv
 {
+  /// Returns the inverse of an element.
   fn inverse(&self) -> Self;
+  /// Inplace version of `inverse`.
   fn invert(&mut self);
 }
diff --git a/src/traits/transpose.rs b/src/traits/transpose.rs
index 459adac2..4eedec92 100644
--- a/src/traits/transpose.rs
+++ b/src/traits/transpose.rs
@@ -1,6 +1,8 @@
 // FIXME: valid only for square matrices…
 pub trait Transpose
 {
+  /// Computes the transpose of a matrix.
   fn transposed(&self) -> Self;
+  /// Inplace version of `transposed`.
   fn transpose(&mut self);
 }