Spelling correction

Triangulation_2/include/CGAL/Constrained_triangulation_plus_2.h

@@ -427,7 +427,7 @@ class Constrained_triangulation_plus_2
     //   cid is [B, P, C]
     //   head is null or [A...B]
     //   tail is null or [C...D]
-    // Let create insert [C,D] and conditionnaly concatenate head and tail,
+    // Let create insert [C,D] and conditionally concatenate head and tail,
     // and return the iterator to C
 
     Vertex_handle b = *std::prev(pos);

Triangulation_2/include/CGAL/Triangulation_2/internal/Polyline_constraint_hierarchy_2.h

@@ -362,7 +362,7 @@ class Polyline_constraint_hierarchy_2
     // - The end value is when `constraint_it` is the end iterator of `constraints_set`.
     //   In that case `vertex_it` must be singular.
     //
-    // - Otherwise all members must be valid pointers or dereferencable iterators.
+    // - Otherwise all members must be valid pointers or dereferenceable iterators.
 
     bool is_singular() const {
       return hierarchy == nullptr;