diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/Is_valid_functor.tex b/Number_types/doc_tex/NumberTypeSupport_ref/Is_valid_functor.tex
new file mode 100644
index 00000000000..aef7a0abd9f
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/Is_valid_functor.tex
@@ -0,0 +1,22 @@
+\begin{ccRefFunctionObjectClass}{Is_valid<T>}
+
+\ccDefinition
+
+Not all values of a type need to be valid. The function object 
+class \ccRefName\ checks this. \\
+
+For example, an expression like
+\ccStyle{NT(0)/NT(0)} can result in an invalid number. 
+Routines may have as a precondition that all values are valid.
+ 
+\ccInclude{CGAL/utils_classes.h}
+
+
+\ccIsModel
+\ccRefConceptPage{AdaptableFunctor}
+
+\ccCreationVariable{operator()}
+\ccMethod{bool operator()(const T& x);}
+{returns if the argument is valid.}
+
+\end{ccRefFunctionObjectClass}
\ No newline at end of file
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/Max_functor.tex b/Number_types/doc_tex/NumberTypeSupport_ref/Max_functor.tex
new file mode 100644
index 00000000000..16aa13dc627
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/Max_functor.tex
@@ -0,0 +1,29 @@
+\begin{ccRefFunctionObjectClass}{Max<T,Compare>}
+
+\ccDefinition
+
+The function object class \ccRefName\ returns the larger of two values.
+The default value for \ccc{Compare} is \ccc{std::less}.\\
+
+Note that \ccc{T} must be a model of \ccc{LessThanComparable}
+in case \ccc{std::less} is used. 
+ 
+\ccInclude{CGAL/utils_classes.h}
+
+\ccIsModel
+\ccRefConceptPage{AdaptableFunctor}
+
+\ccCreation
+\ccCreationVariable{max}
+\ccConstructor{Max();}{ default constructor. }
+\ccGlue
+\ccConstructor{Max(Compare c);}
+        {The constructed object will use \ccc{c} to compare the arguments. }
+
+\ccOperations
+\ccCreationVariable{operator()}
+\ccMethod{T operator()(const T& x, const T& y);}
+{returns the larger of \ccc{x} and \ccc{y}, 
+with respect to the order induced by \ccc{Compare}. }
+
+\end{ccRefFunctionObjectClass}
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/Min_functor.tex b/Number_types/doc_tex/NumberTypeSupport_ref/Min_functor.tex
new file mode 100644
index 00000000000..a46087425eb
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/Min_functor.tex
@@ -0,0 +1,29 @@
+\begin{ccRefFunctionObjectClass}{Min<T,Compare>}
+
+\ccDefinition
+
+The function object class \ccRefName\ returns the smaller of two values.
+The default value for \ccc{Compare} is \ccc{std::less}.\\
+
+Note that \ccc{T} must be a model of \ccc{LessThanComparable}
+in case \ccc{std::less} is used. 
+ 
+\ccInclude{CGAL/utils_classes.h}
+
+\ccIsModel
+\ccRefConceptPage{AdaptableFunctor}
+
+\ccCreation
+\ccCreationVariable{min}
+\ccConstructor{Min();}{ default constructor. } 
+\ccGlue
+\ccConstructor{Min(Compare c);}
+        {The constructed object will use \ccc{c} to compare the arguments. }
+
+\ccOperations
+\ccCreationVariable{operator()}
+\ccMethod{T operator()(const T& x, const T& y);}
+{returns the larger of \ccc{x} and \ccc{y}, 
+with respect to the order induced by \ccc{Compare}. }
+
+\end{ccRefFunctionObjectClass}
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/intro.tex b/Number_types/doc_tex/NumberTypeSupport_ref/intro.tex
index 54296e77256..e33591d6591 100644
--- a/Number_types/doc_tex/NumberTypeSupport_ref/intro.tex
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/intro.tex
@@ -56,4 +56,11 @@
 \ccRefIdfierPage{CGAL::Root_of_traits_2<RT>}\\
 \ccRefIdfierPage{CGAL::make_root_of_2}\\
 
+\subsection*{Utilities} 
+\ccRefIdfierPage{Min}\\
+\ccRefIdfierPage{Max}\\
+\ccRefIdfierPage{Is_valid}\\ 
+\ccRefIdfierPage{min}\\
+\ccRefIdfierPage{max}\\
+\ccRefIdfierPage{is_valid}\\
 %% EOF
\ No newline at end of file
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/is_valid.tex b/Number_types/doc_tex/NumberTypeSupport_ref/is_valid.tex
new file mode 100644
index 00000000000..082cac2a6ea
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/is_valid.tex
@@ -0,0 +1,16 @@
+\begin{ccRefFunction}{is_valid}
+
+\ccDefinition
+
+Not all values of a type need to be valid.
+The function \ccRefName\ returns whether the argument is valid. 
+
+\ccInclude{CGAL/utils.h}
+
+\ccFunction{bool is_valid(const T& x);}{}
+
+\ccSeeAlso
+
+\ccRefIdfierPage{Is_valid}\\
+
+\end{ccRefFunction}
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/main.tex b/Number_types/doc_tex/NumberTypeSupport_ref/main.tex
index b91cf44cf58..0880e580166 100644
--- a/Number_types/doc_tex/NumberTypeSupport_ref/main.tex
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/main.tex
@@ -32,6 +32,14 @@
 \input{NumberTypeSupport_ref/Number_type_checker.tex}
 \input{NumberTypeSupport_ref/Sqrt_extension.tex}
 
+%functors
+\input{NumberTypeSupport_ref/Max_functor.tex}
+\input{NumberTypeSupport_ref/Min_functor.tex}
+\input{NumberTypeSupport_ref/Is_valid_functor.tex}
+%functions
+\input{NumberTypeSupport_ref/max.tex}
+\input{NumberTypeSupport_ref/min.tex}
+\input{NumberTypeSupport_ref/is_valid.tex}
 
 \input{NumberTypeSupport_ref/Rational_traits.tex }
 \input{NumberTypeSupport_ref/simplest_rational_in_interval.tex }
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/max.tex b/Number_types/doc_tex/NumberTypeSupport_ref/max.tex
new file mode 100644
index 00000000000..6196ee656a5
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/max.tex
@@ -0,0 +1,13 @@
+\begin{ccRefFunction}{max}
+
+\ccDefinition
+
+The function \ccRefName\ returns the larger of two values.
+
+\ccInclude{CGAL/utils.h}
+
+\ccFunction{T max(const T& x, const T& y);}{}
+
+\ccRefIdfierPage{Max}\\
+
+\end{ccRefFunction}
diff --git a/Number_types/doc_tex/NumberTypeSupport_ref/min.tex b/Number_types/doc_tex/NumberTypeSupport_ref/min.tex
new file mode 100644
index 00000000000..149348b30ee
--- /dev/null
+++ b/Number_types/doc_tex/NumberTypeSupport_ref/min.tex
@@ -0,0 +1,15 @@
+\begin{ccRefFunction}{min}
+
+\ccDefinition
+
+The function \ccRefName\ returns the smaller of two values.
+
+\ccInclude{CGAL/utils.h}
+
+\ccFunction{T min(const T& x, const T& y);}{}
+
+\ccSeeAlso
+
+\ccRefIdfierPage{Min}\\
+
+\end{ccRefFunction}