diff --git a/Arrangement_2/doc_tex/Arrangement_2/arr_intro.tex b/Arrangement_2/doc_tex/Arrangement_2/arr_intro.tex
index 021e1558f7b..9ec7730bf8d 100644
--- a/Arrangement_2/doc_tex/Arrangement_2/arr_intro.tex
+++ b/Arrangement_2/doc_tex/Arrangement_2/arr_intro.tex
@@ -41,7 +41,7 @@ maintains the incidence relations among these objects.
 
 The main idea behind the \dcel\ data-structure is to represent
 each edge using a pair of directed {\em halfedges}, one going from
-the the $xy$-lexicographically smaller (left) endpoint of the curve toward
+the $xy$-lexicographically smaller (left) endpoint of the curve toward
 its the $xy$-lexicographically larger (right) endpoint, and the other,
 known as its {\em twin} halfedge, going in the opposite direction. As each
 halfedge is directed, we say it has a {\em source} vertex and a {\em target}
diff --git a/Arrangement_2/doc_tex/Arrangement_2/arr_traits.tex b/Arrangement_2/doc_tex/Arrangement_2/arr_traits.tex
index ef89a33b353..40312d6b4c5 100644
--- a/Arrangement_2/doc_tex/Arrangement_2/arr_traits.tex
+++ b/Arrangement_2/doc_tex/Arrangement_2/arr_traits.tex
@@ -220,7 +220,7 @@ class-template with the predefined
 \ccc{Exact_predicates_inexact_constructions_kernel}. Note that we use
 the \ccc{insert_non_intersecting_curves()} function to construct the
 arrangement.
-By default, the example opens the the \ccc{Europe.dat} input-file,
+By default, the example opens the \ccc{Europe.dat} input-file,
 located in the examples folder, which contains more than $3000$ line segments
 with floating-point coordinates that form the map of Europe, as depicted in
 Figure~\ref{arr_fig:predef_kernels}(b):
diff --git a/Arrangement_2/doc_tex/Arrangement_2_ref/Arr_halfedge.tex b/Arrangement_2/doc_tex/Arrangement_2_ref/Arr_halfedge.tex
index 297b431285c..40ab5cb051a 100644
--- a/Arrangement_2/doc_tex/Arrangement_2_ref/Arr_halfedge.tex
+++ b/Arrangement_2/doc_tex/Arrangement_2_ref/Arr_halfedge.tex
@@ -46,7 +46,7 @@ that return constant handles, iterators or circulators:
     {returns a handle for the source vertex of \ccVar{}.}
 \ccGlue
 \ccMethod{Vertex_handle target();}
-    {returns a handle for the the target vertex of \ccVar{}.}
+    {returns a handle for the target vertex of \ccVar{}.}
 
 \ccMethod{Comparison_result direction() const;}
     {returns the direction of the halfedge: \ccc{SMALLER} if \ccVar{}'s
diff --git a/Kernel_d/doc_tex/Convex_hull_d_ref/Convex_hull_d.tex b/Kernel_d/doc_tex/Convex_hull_d_ref/Convex_hull_d.tex
index 22c6420718b..07ef7afc5b1 100644
--- a/Kernel_d/doc_tex/Convex_hull_d_ref/Convex_hull_d.tex
+++ b/Kernel_d/doc_tex/Convex_hull_d_ref/Convex_hull_d.tex
@@ -75,7 +75,7 @@ Note that each iterator fits the handle concept, i.e. iterators can be
 used as handles. Note also that all iterator and handle types come
 also in a const flavor, e.g., \ccc{Vertex_const_iterator} is the
 constant version of \ccc{Vertex_iterator}. Const correctness requires
-to use the const version whenever the the convex hull object is
+to use the const version whenever the convex hull object is
 referenced as constant. The \ccc{Hull_vertex_iterator} is convertible
 to \ccc{Vertex_iterator} and \ccc{Vertex_handle}.
 
diff --git a/Kernel_d/doc_tex/Kernel_d/kernel_representation_d.tex b/Kernel_d/doc_tex/Kernel_d/kernel_representation_d.tex
index 85dae66c094..6d24390e1c0 100644
--- a/Kernel_d/doc_tex/Kernel_d/kernel_representation_d.tex
+++ b/Kernel_d/doc_tex/Kernel_d/kernel_representation_d.tex
@@ -214,7 +214,7 @@ due to accumulated rounding errors.
 
 \subsection{Inclusion of Header Files}
 
-You need just to include a representation class to obtain the the
+You need just to include a representation class to obtain the
 geometric objects of the kernel that you would like to use with the
 representation class, i.e., \ccc{CGAL/Cartesian_d.h} or
 \ccc{CGAL/Homogeneous_d.h}
diff --git a/Kinetic_data_structures/doc_tex/Kinetic_data_structures/sorted_impl_example.tex b/Kinetic_data_structures/doc_tex/Kinetic_data_structures/sorted_impl_example.tex
index 4e9af191c73..413846caaca 100644
--- a/Kinetic_data_structures/doc_tex/Kinetic_data_structures/sorted_impl_example.tex
+++ b/Kinetic_data_structures/doc_tex/Kinetic_data_structures/sorted_impl_example.tex
@@ -180,7 +180,7 @@ a notification. Validation consists of using the
 ordered correctly.
 
 The remaining two methods, \ccc{set} and \ccc{erase} are only
-necessary if the the kinetic data structure wishes to support dynamic
+necessary if the kinetic data structure wishes to support dynamic
 trajectory changes and removals. These methods are called by the
 \ccc{mot_listener_} helper when appropriate.
 
diff --git a/Kinetic_data_structures/doc_tex/Kinetic_data_structures/trivial_kds_example.tex b/Kinetic_data_structures/doc_tex/Kinetic_data_structures/trivial_kds_example.tex
index cf3af305e50..f8cee4ee5db 100644
--- a/Kinetic_data_structures/doc_tex/Kinetic_data_structures/trivial_kds_example.tex
+++ b/Kinetic_data_structures/doc_tex/Kinetic_data_structures/trivial_kds_example.tex
@@ -10,7 +10,7 @@ kinetic data structure so that the \ccc{operator<<} can be defined for
 them. 
 
 The kinetic data structure maintains one event containing a list of
-the trajectories of all objects in the the simulation. This
+the trajectories of all objects in the simulation. This
 event must updated whenever any objects change, in addition, it is
 always created to fail one time unit in the future, so it must be
 recreated when it fails. As a result, the kinetic data structure has
diff --git a/Nef_3/doc_tex/Nef_3_ref/Nef_polyhedron_3_Halfedge.tex b/Nef_3/doc_tex/Nef_3_ref/Nef_polyhedron_3_Halfedge.tex
index 759536e172f..29016838fff 100644
--- a/Nef_3/doc_tex/Nef_3_ref/Nef_polyhedron_3_Halfedge.tex
+++ b/Nef_3/doc_tex/Nef_3_ref/Nef_polyhedron_3_Halfedge.tex
@@ -44,7 +44,7 @@ function \ccc{twin()} returns the opposite halfedge.
 
 Looking at the incidence structure on a sphere map, the member function 
 \ccc{out_sedge} returns the first outgoing shalfedge, and \ccc{incident_sface}
-returns the the incident sface.
+returns the incident sface.
 
 \ccInclude{CGAL/Nef_polyhedron_3.h}
 
diff --git a/Nef_S2/doc_tex/Nef_S2_ref/Nef_polyhedron_S2_SVertex.tex b/Nef_S2/doc_tex/Nef_S2_ref/Nef_polyhedron_S2_SVertex.tex
index caab923ff43..cbd281e1a8c 100644
--- a/Nef_S2/doc_tex/Nef_S2_ref/Nef_polyhedron_S2_SVertex.tex
+++ b/Nef_S2/doc_tex/Nef_S2_ref/Nef_polyhedron_S2_SVertex.tex
@@ -27,7 +27,7 @@ The figure on page
 
 The member function 
 \ccc{out_sedge} returns the first outgoing shalfedge, and \ccc{incident_sface}
-returns the the incident sface.
+returns the incident sface.
 
 \ccInclude{CGAL/Nef_polyhedron_S2.h}
 
diff --git a/Partition_2/doc_tex/Partition_2_ref/greene_approx_convex_partition_2.tex b/Partition_2/doc_tex/Partition_2_ref/greene_approx_convex_partition_2.tex
index 239a2ed2628..4b2fd78d8df 100644
--- a/Partition_2/doc_tex/Partition_2_ref/greene_approx_convex_partition_2.tex
+++ b/Partition_2/doc_tex/Partition_2_ref/greene_approx_convex_partition_2.tex
@@ -63,7 +63,7 @@ with the representation type determined by \ccc{InputIterator::value_type}.
 \ccRefIdfierPage{CGAL::y_monotone_partition_2} 
 
 \ccImplementation
-This function implements the the approximation algorithm of 
+This function implements the approximation algorithm of 
 Greene \cite{g-dpcp-83} and requires $O(n \log n)$ time and $O(n)$ space
 to produce a convex partitioning given a $y$-monotone partitioning of a
 polygon with $n$ vertices.  The function \ccc{y_monotone_partition_2} 
diff --git a/Polygon/doc_tex/Polygon_ref/right_vertex_2.tex b/Polygon/doc_tex/Polygon_ref/right_vertex_2.tex
index 3a17a721f8f..428d7c30dac 100644
--- a/Polygon/doc_tex/Polygon_ref/right_vertex_2.tex
+++ b/Polygon/doc_tex/Polygon_ref/right_vertex_2.tex
@@ -37,7 +37,7 @@ with the largest \ccStyle{y}-coordinate is taken.
 \begin{enumerate}
     \item \ccc{Traits} is a model of the concept 
 	  PolygonTraits\_2\ccIndexMainItem[c]{PolygonTraits_2}.
-	  In fact, only the the members \ccc{Less_xy_2} and
+	  In fact, only the members \ccc{Less_xy_2} and
 	  \ccc{less_xy_2_object} are used.
     \item \ccc{ForwardIterator::value_type} should be \ccc{Traits::Point_2},
 \end{enumerate}
diff --git a/Polygon/doc_tex/Polygon_ref/top_vertex_2.tex b/Polygon/doc_tex/Polygon_ref/top_vertex_2.tex
index 364506995f4..16ab944bd82 100644
--- a/Polygon/doc_tex/Polygon_ref/top_vertex_2.tex
+++ b/Polygon/doc_tex/Polygon_ref/top_vertex_2.tex
@@ -37,7 +37,7 @@ with the largest \ccStyle{x}-coordinate is taken.
 \begin{enumerate}
     \item \ccc{Traits} is a model of the concept 
 	  PolygonTraits\_2\ccIndexMainItem[c]{PolygonTraits_2}.
-	  In fact, only the the members \ccc{Less_yx_2} and
+	  In fact, only the members \ccc{Less_yx_2} and
 	  \ccc{less_yx_2_object} are used.
     \item \ccc{ForwardIterator::value_type} should be \ccc{Traits::Point_2},
 \end{enumerate}
diff --git a/Polygonal_approximation_d/doc_tex/Polygonal_approximation_d/main.tex b/Polygonal_approximation_d/doc_tex/Polygonal_approximation_d/main.tex
index c93ac570859..52d58f3b28c 100755
--- a/Polygonal_approximation_d/doc_tex/Polygonal_approximation_d/main.tex
+++ b/Polygonal_approximation_d/doc_tex/Polygonal_approximation_d/main.tex
@@ -29,7 +29,7 @@ polyline and the simplified polyline, or as the sum of all
 these distances.
 
 Although the interface is generic, this package implements faster algorithms
-for the the Euclidean distance, namely the incremental algorithm \cite{[cgal:pv-opadc-94]},
+for the Euclidean distance, namely the incremental algorithm \cite{[cgal:pv-opadc-94]},
 and the algorithm based on the path hull structure \cite{[hs-sudpl-92]}.
 
 Finally, another group of algorithms, optimal polyline simplification methods
diff --git a/QP_solver/doc_tex/Optimisation_ref/QP_pricing_strategy.tex b/QP_solver/doc_tex/Optimisation_ref/QP_pricing_strategy.tex
index a07298cc65d..40e7efacd12 100644
--- a/QP_solver/doc_tex/Optimisation_ref/QP_pricing_strategy.tex
+++ b/QP_solver/doc_tex/Optimisation_ref/QP_pricing_strategy.tex
@@ -46,7 +46,7 @@ internals.}
 %the bounds themselves can be evaluated with floating point arithmetic. 
 
 User provided pricing strategies may use \ccRefName\ as a base class directly
-or inherit from the the class \ccc{QP__filtered_base} or from the class
+or inherit from the class \ccc{QP__filtered_base} or from the class
 \ccc{QP__partial_base} or both.   
    
 
diff --git a/QP_solver/doc_tex/Optimisation_ref/QP_solver.tex b/QP_solver/doc_tex/Optimisation_ref/QP_solver.tex
index 3a4618c37eb..3deac4eea91 100644
--- a/QP_solver/doc_tex/Optimisation_ref/QP_solver.tex
+++ b/QP_solver/doc_tex/Optimisation_ref/QP_solver.tex
@@ -265,7 +265,7 @@ solution, see \ccc{variables_value_begin()} below.}
 %KKT
 %\ccNestedType{Lambda_value_iterator}{a STL random access iterator with value type}
 
-%The following enum type is provided by the the class \ccRefName\ :
+%The following enum type is provided by the class \ccRefName\ :
 
 \ccEnum{enum Strategy { FULL_EXACT_PRICING, FULL_FILTERED_PRICING,
 PARTIAL_EXACT_PRICING, PARTIAL_FILTERED_PRICING };}{enumeration used
diff --git a/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/SegmentDelaunayGraphTraits_2.tex b/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/SegmentDelaunayGraphTraits_2.tex
index c6bc931e7af..55730285254 100644
--- a/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/SegmentDelaunayGraphTraits_2.tex
+++ b/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/SegmentDelaunayGraphTraits_2.tex
@@ -229,7 +229,7 @@ and has as endpoints the Voronoi vertices $v_{\infty{}12}$ and
 $v_{\infty{}31}$ defined by the triplets
 $s_\infty$, \ccc{s1}, \ccc{s2} and $s_\infty$, \ccc{s3} and
 \ccc{s1}. The sign \ccc{sgn} is the common sign of the distances of
-\ccc{q} from the Voronoi circles centered at the the vertices
+\ccc{q} from the Voronoi circles centered at the vertices
 $v_{\infty{}12}$ and $v_{\infty{}31}$. If \ccc{sgn} is \ccc{NEGATIVE},
 the predicate returns \ccc{true} if and only if the entire Voronoi
 edge is in conflict with \ccc{q}. If \ccc{sgn} is \ccc{POSITIVE} or
diff --git a/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/Segment_Delaunay_graph_2.tex b/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/Segment_Delaunay_graph_2.tex
index 1e5d691711d..ef32e9cc004 100644
--- a/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/Segment_Delaunay_graph_2.tex
+++ b/Segment_Delaunay_graph_2/doc_tex/Segment_Delaunay_graph_2_ref/Segment_Delaunay_graph_2.tex
@@ -222,7 +222,7 @@ Gt gt=Gt());}
 {Returns the number of finite vertices of the segment Delaunay graph.}
 \ccGlue
 \ccMethod{size_type number_of_faces();}
-{Returns the number of faces (both finite and infinite) of the the
+{Returns the number of faces (both finite and infinite) of the
   segment Delaunay graph.}
 \ccGlue
 \ccMethod{size_type number_of_input_sites();}
diff --git a/Spatial_searching/doc_tex/Spatial_searching/intro.tex b/Spatial_searching/doc_tex/Spatial_searching/intro.tex
index b188ee580e1..ee2e42a1d90 100755
--- a/Spatial_searching/doc_tex/Spatial_searching/intro.tex
+++ b/Spatial_searching/doc_tex/Spatial_searching/intro.tex
@@ -129,7 +129,7 @@ browsing for queries defined by points or spatial objects.
 supported using exact or fuzzy $d$-dimensional objects enclosing a
 region.  The fuzziness of the query object is specified by a parameter
 $\epsilon$ denoting a maximal allowed distance to the boundary of a
-query object.  If the distance to the the boundary is at least
+query object.  If the distance to the boundary is at least
 $\epsilon$, points inside the object are always reported and points
 outside the object are never reported. Points within distance
 $\epsilon$ to the boundary may be or may be not reported.  For exact
diff --git a/Triangulation_2/doc_tex/TDS_2/tds_user.tex b/Triangulation_2/doc_tex/TDS_2/tds_user.tex
index 12b71d7cc7a..8ab08eb460e 100644
--- a/Triangulation_2/doc_tex/TDS_2/tds_user.tex
+++ b/Triangulation_2/doc_tex/TDS_2/tds_user.tex
@@ -117,7 +117,7 @@ The triangulation data structure
 is required to provide :
 \begin{itemize}
 \item
-the types \ccc{Vertex} and \ccc{Face} for the the vertices
+the types \ccc{Vertex} and \ccc{Face} for the vertices
 and faces of the triangulations
 \item the type \ccc{Vertex_handle} and \ccc{Face_handle}
 which are models of the concept \ccc{Handle} and 
diff --git a/Triangulation_2/doc_tex/Triangulation_2_ref/Regular_triangulation_2.tex b/Triangulation_2/doc_tex/Triangulation_2_ref/Regular_triangulation_2.tex
index 78b17f86f6b..55c57c4183b 100644
--- a/Triangulation_2/doc_tex/Triangulation_2_ref/Regular_triangulation_2.tex
+++ b/Triangulation_2/doc_tex/Triangulation_2_ref/Regular_triangulation_2.tex
@@ -267,7 +267,7 @@ located in  \ccc{lt,loc,li}.}
   get_boundary_of_conflicts_and_hidden_vertices(const Weighted_point
   &p, OutputItBoundaryEdges eit,
   OutputItHiddenVertices vit, Face_handle start) const;} 
-{ same as above except that only the the vertices that would be hidden
+{ same as above except that only the vertices that would be hidden
   by \ccc{p} and the boundary of the zone in conflict with \ccc{p} are
   output via the corresponding output iterators. The boundary edges of
   the conflict zone are ouput in counterclockwise order and each edge
diff --git a/Triangulation_2/doc_tex/Triangulation_2_ref/Triangulation_2.tex b/Triangulation_2/doc_tex/Triangulation_2_ref/Triangulation_2.tex
index cf63f955388..cdfcb452ad9 100644
--- a/Triangulation_2/doc_tex/Triangulation_2_ref/Triangulation_2.tex
+++ b/Triangulation_2/doc_tex/Triangulation_2_ref/Triangulation_2.tex
@@ -809,7 +809,7 @@ to \ccc{v}.}
 to \ccc{v}.}
 \ccGlue
 \ccMethod{Edge_circulator incident_edges(Vertex_handle v, Face_handle f) const;}
-{Starts at the the first edge of \ccc{f} incident to 
+{Starts at the first edge of \ccc{f} incident to 
 \ccc{v}, in counterclockwise order around \ccc{v}.
 \ccPrecond Face \ccc{f} is incident to vertex \ccc{v}.}
 \ccGlue
diff --git a/Viewer_3/doc_tex/Viewer_3/viewer.tex b/Viewer_3/doc_tex/Viewer_3/viewer.tex
index e742d2172df..6940f48a0b1 100644
--- a/Viewer_3/doc_tex/Viewer_3/viewer.tex
+++ b/Viewer_3/doc_tex/Viewer_3/viewer.tex
@@ -162,7 +162,7 @@ on the left of the browser.
 \subsection{The user panel}
 
 Users can define their own buttons and actions in a special panel
-activated by the the ``User Panel'' button. By default, there is nothing 
+activated by the ``User Panel'' button. By default, there is nothing 
 but a ``Close'' button in this panel.
 
 \section{The drawable objects}
diff --git a/Visibility_complex/doc_tex/Visibility_complex/main.tex b/Visibility_complex/doc_tex/Visibility_complex/main.tex
index 358c57dfd6d..5fdd6124eb7 100644
--- a/Visibility_complex/doc_tex/Visibility_complex/main.tex
+++ b/Visibility_complex/doc_tex/Visibility_complex/main.tex
@@ -471,7 +471,7 @@ The shortest path is computed as follows:
     \item Perform a Dijsktra algorithm to find the shortest path between $p$ and
     $q$.
 \end{enumerate}
-The value type of the output iterator is the vertex type of the the visibility
+The value type of the output iterator is the vertex type of the visibility
 complex computed in the second step above. In other words we only give access to
 the bitangent segments of the shortest path (recall that the vertices of the
 visibility complex correspond to free bitangents).