diff --git a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_3.h b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_3.h
index 4d88721cc77..ede8f7c829e 100644
--- a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_3.h
+++ b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_3.h
@@ -9,9 +9,9 @@ If `origin` is given then it must be a point strictly inside the polyhedron. If
 This version does not construct the dual points explicitely but uses a special traits class for the function `CGAL::convex_hull_3()` to handle predicates on dual points without constructing them.
 
 \attention Halfspaces are considered as lower halfspaces that is to say if the plane's equation is \f$ a\, x +b\, y +c\, z + d = 0 \f$ then the corresponding halfspace is defined by \f$ a\, x +b\, y +c\, z + d \le 0 \f$ .
-\attention The point type of `origin` and the point type of the vertices of `Polyhedron` must come from the same \cgal %Kernel.
+\attention 
 
-\pre if provided, `origin` is inside the intersection of halfspaces defined by the range `[begin, end)`.
+\pre The point type of `origin` and the point type of the vertices of `Polyhedron` must come from the same \cgal %Kernel.\pre if provided, `origin` is inside the intersection of halfspaces defined by the range `[begin, end)`.
 \pre The computed intersection must be a bounded convex polyhedron.
 
 \tparam PlaneIterator must be an input iterator where the value type must be `Polyhedron::Traits::Plane_3`
diff --git a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_with_constructions_3.h b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_with_constructions_3.h
index 832a39908be..23fdf55ae4a 100644
--- a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_with_constructions_3.h
+++ b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_3/dual/halfspace_intersection_with_constructions_3.h
@@ -8,8 +8,8 @@ If `origin` is given then it must be a point strictly inside the polyhedron. If
 This version constructs explicitly the dual points using the convex hull algorithm parametrized with the given traits class.
 
 \attention Halfspaces are considered as lower halfspaces that is to say if the plane's equation is \f$ a\, x +b\, y +c\, z + d = 0 \f$ then the corresponding halfspace is defined by \f$ a\, x +b\, y +c\, z + d \le 0 \f$ .
-\attention The value type of `PlaneIterator` and the point type of `origin` must come from the same \cgal Kernel.
 
+\pre The value type of `PlaneIterator` and the point type of `origin` must come from the same \cgal Kernel.
 \pre if provided, `origin` is inside the intersection of halfspaces defined by the range `[begin, end)`.
 \pre The computed intersection must be a bounded convex polyhedron.