Tutorial: Refactor MathFunctions code

Propagate the refactor in Step 10 MathFunctions through all of the
steps. Use MathFunctions/MathFunctions.cxx instead of Tutorial.cxx
to determine which sqrt library is called. Adds .h files which
correspond to their .cxx files by name.

81 files changed, 645 insertions, 516 deletions

diff --git a/Help/guide/tutorial/A Basic Starting Point.rst b/Help/guide/tutorial/A Basic Starting Point.rst
index 3dac68a80f..37b0668d4e 100644
--- a/Help/guide/tutorial/A Basic Starting Point.rst
+++ b/Help/guide/tutorial/A Basic Starting Point.rst
@@ -160,7 +160,7 @@ The last command to call for a basic project is
   :name: CMakeLists.txt-add_executable
   :language: cmake
   :start-after: # add the executable
-  :end-before: # TODO 9:
+  :end-before: # TODO 3:
 
 .. raw:: html
 
@@ -240,7 +240,7 @@ the following:
   :name: tutorial.cxx-cxx11
   :language: c++
   :start-after: // convert input to double
-  :end-before: // TODO 12:
+  :end-before: // TODO 6:
 
 .. raw:: html
 
@@ -265,7 +265,7 @@ add the :variable:`CMAKE_CXX_STANDARD` declarations above the call to
   :name: CMakeLists.txt-CXX_STANDARD
   :language: cmake
   :start-after: # specify the C++ standard
-  :end-before: # TODO 7:
+  :end-before: # configure a header file
 
 .. raw:: html
 
@@ -375,7 +375,7 @@ specified CMake variables replaced:
   :name: CMakeLists.txt-configure_file
   :language: cmake
   :start-after: # to the source code
-  :end-before: # TODO 8:
+  :end-before: # TODO 2:
 
 .. raw:: html
 
@@ -420,7 +420,6 @@ be replaced with the corresponding version numbers from the project in
   :caption: TODO 10: TutorialConfig.h.in
   :name: TutorialConfig.h.in
   :language: c++
-  :end-before: // TODO 13:
 
 .. raw:: html
 
diff --git a/Help/guide/tutorial/Adding Generator Expressions.rst b/Help/guide/tutorial/Adding Generator Expressions.rst
index 6f9714e474..08f3eead33 100644
--- a/Help/guide/tutorial/Adding Generator Expressions.rst
+++ b/Help/guide/tutorial/Adding Generator Expressions.rst
@@ -299,7 +299,7 @@ condition. The resulting full code looks like the following:
   :name: CMakeLists.txt-target_compile_options-genex
   :language: cmake
   :start-after: set(msvc_cxx "$<COMPILE_LANG_AND_ID:CXX,MSVC>")
-  :end-before: # should we use our own math functions
+  :end-before: # configure a header file to pass some of the CMake settings
 
 .. raw:: html
 
diff --git a/Help/guide/tutorial/Adding System Introspection.rst b/Help/guide/tutorial/Adding System Introspection.rst
index b69abd2920..b3147736a3 100644
--- a/Help/guide/tutorial/Adding System Introspection.rst
+++ b/Help/guide/tutorial/Adding System Introspection.rst
@@ -119,7 +119,7 @@ our source code can tell what resources are available. If both ``log`` and
   :name: MathFunctions/CMakeLists.txt-target_compile_definitions
   :language: cmake
   :start-after: # add compile definitions
-  :end-before: # install libs
+  :end-before: # state
 
 .. raw:: html
 
@@ -136,7 +136,8 @@ Since we may be using ``log`` and ``exp``, we need to modify
   :caption: TODO 4: MathFunctions/mysqrt.cxx
   :name: MathFunctions/mysqrt.cxx-include-cmath
   :language: c++
-  :end-before: #include <iostream>
+  :start-after: #include "mysqrt.h"
+  :end-before: include <iostream>
 
 .. raw:: html
 
diff --git a/Help/guide/tutorial/Adding Usage Requirements for a Library.rst b/Help/guide/tutorial/Adding Usage Requirements for a Library.rst
index 4aef050585..74b7496688 100644
--- a/Help/guide/tutorial/Adding Usage Requirements for a Library.rst
+++ b/Help/guide/tutorial/Adding Usage Requirements for a Library.rst
@@ -100,7 +100,7 @@ follows:
   :name: MathFunctions/CMakeLists.txt-target_include_directories-INTERFACE
   :language: cmake
   :start-after: # to find MathFunctions.h
-  :end-before: # TODO 3: Link to
+  :end-before: option
 
 .. raw:: html
 
@@ -119,7 +119,7 @@ safely remove our uses of the ``EXTRA_INCLUDES`` variable from the top-level
   :name: CMakeLists.txt-remove-EXTRA_INCLUDES
   :language: cmake
   :start-after: # add the MathFunctions library
-  :end-before: # add the executable
+  :end-before: # TODO 2: Link to tutorial_compiler_flags
 
 .. raw:: html
 
diff --git a/Help/guide/tutorial/Adding a Custom Command and Generated File.rst b/Help/guide/tutorial/Adding a Custom Command and Generated File.rst
index b1f984076d..9e6311e574 100644
--- a/Help/guide/tutorial/Adding a Custom Command and Generated File.rst
+++ b/Help/guide/tutorial/Adding a Custom Command and Generated File.rst
@@ -23,15 +23,25 @@ The next step is to add the appropriate commands to the
 then run it as part of the build process. A few commands are needed to
 accomplish this.
 
-First, at the top of ``MathFunctions/CMakeLists.txt``, the executable for
-``MakeTable`` is added as any other executable would be added.
+First, in the ``USE_MYMATH`` section of ``MathFunctions/CMakeLists.txt``,
+we add an executable for ``MakeTable``.
 
 .. literalinclude:: Step9/MathFunctions/CMakeLists.txt
   :caption: MathFunctions/CMakeLists.txt
   :name: MathFunctions/CMakeLists.txt-add_executable-MakeTable
   :language: cmake
   :start-after: # first we add the executable that generates the table
-  :end-before: # add the command to generate the source code
+  :end-before: target_link_libraries
+
+After creating the executable, we add the ``tutorial_compiler_flags`` to our
+executable using :command:`target_link_libraries`.
+
+.. literalinclude:: Step9/MathFunctions/CMakeLists.txt
+  :caption: MathFunctions/CMakeLists.txt
+  :name: MathFunctions/CMakeLists.txt-link-tutorial-compiler-flags
+  :language: cmake
+  :start-after: add_executable
+  :end-before: # add the command to generate
 
 Then we add a custom command that specifies how to produce ``Table.h``
 by running MakeTable.
@@ -41,7 +51,7 @@ by running MakeTable.
   :name: MathFunctions/CMakeLists.txt-add_custom_command-Table.h
   :language: cmake
   :start-after: # add the command to generate the source code
-  :end-before: # add the main library
+  :end-before: # library that just does sqrt
 
 Next we have to let CMake know that ``mysqrt.cxx`` depends on the generated
 file ``Table.h``. This is done by adding the generated ``Table.h`` to the list
@@ -51,8 +61,8 @@ of sources for the library MathFunctions.
   :caption: MathFunctions/CMakeLists.txt
   :name: MathFunctions/CMakeLists.txt-add_library-Table.h
   :language: cmake
-  :start-after: # add the main library
-  :end-before: # state that anybody linking
+  :start-after:   # library that just does sqrt
+  :end-before: # state that we depend on
 
 We also have to add the current binary directory to the list of include
 directories so that ``Table.h`` can be found and included by ``mysqrt.cxx``.
@@ -62,7 +72,19 @@ directories so that ``Table.h`` can be found and included by ``mysqrt.cxx``.
   :name: MathFunctions/CMakeLists.txt-target_include_directories-Table.h
   :language: cmake
   :start-after: # state that we depend on our bin
-  :end-before: # install libs
+  :end-before: target_link_libraries
+
+As the last thing in our ``USE_MYMATH`` section, we need to link the our
+flags onto ``SqrtLibrary`` and then link ``SqrtLibrary`` onto
+``MathFunctions``. This makes the resulting ``USE_MYMATH`` section look like
+the following:
+
+.. literalinclude:: Step9/MathFunctions/CMakeLists.txt
+  :caption: MathFunctions/CMakeLists.txt
+  :name: MathFunctions/CMakeLists.txt-full_USE_MYMATH-section
+  :language: cmake
+  :start-after: if (USE_MYMATH)
+  :end-before: endif()
 
 Now let's use the generated table. First, modify ``mysqrt.cxx`` to include
 ``Table.h``. Next, we can rewrite the ``mysqrt`` function to use the table:
diff --git a/Help/guide/tutorial/Adding a Library.rst b/Help/guide/tutorial/Adding a Library.rst
index a56c327ee6..2dd731f7f7 100644
--- a/Help/guide/tutorial/Adding a Library.rst
+++ b/Help/guide/tutorial/Adding a Library.rst
@@ -51,11 +51,13 @@ then use this library instead of the standard square root function provided by
 the compiler.
 
 For this tutorial we will put the library into a subdirectory called
-``MathFunctions``. This directory already contains a header file,
-``MathFunctions.h``, and a source file ``mysqrt.cxx``. We will not need to
-modify either of these files. The source file has one function called
+``MathFunctions``. This directory already contains the header files
+``MathFunctions.h`` and ``mysqrt.h``. Their respective source files
+``MathFunctions.cxx`` and ``mysqrt.cxx`` are also provided. We will not need
+to modify any of these files. ``mysqrt.cxx`` has one function called
 ``mysqrt`` that provides similar functionality to the compiler's ``sqrt``
-function.
+function. ``MathFunctions.cxx`` contains one function ``sqrt`` which serves
+to hide the implementation details of ``sqrt``.
 
 From the ``Help/guide/tutorial/Step2`` directory, start with ``TODO 1`` and
 complete through ``TODO 6``.
@@ -91,10 +93,10 @@ Solution
 
 In the ``CMakeLists.txt`` file in the ``MathFunctions`` directory, we create
 a library target called ``MathFunctions`` with :command:`add_library`. The
-source file for the library is passed as an argument to
+source files for the library are passed as an argument to
 :command:`add_library`. This looks like the following line:
 
-.. raw:: html
+.. raw:: html/
 
   <details><summary>TODO 1: Click to show/hide answer</summary>
 
@@ -171,36 +173,40 @@ Now let's use our library. In ``tutorial.cxx``, include ``MathFunctions.h``:
 
   <details><summary>TODO 5: Click to show/hide answer</summary>
 
-.. code-block:: c++
-  :caption: TODO 5 : tutorial.cxx
-  :name: tutorial.cxx-include_MathFunctions.h
-
-  #include "MathFunctions.h"
+.. literalinclude:: Step3/tutorial.cxx
+  :caption: TODO 5: tutorial.cxx
+  :name: CMakeLists.txt-include-MathFunctions.h
+  :language: cmake
+  :start-after: #include <string>
+  :end-before: #include "TutorialConfig.h"
 
 .. raw:: html
 
   </details>
 
-Lastly, replace ``sqrt`` with our library function ``mysqrt``.
+Lastly, replace ``sqrt`` with our library function ``mathfunctions::mysqrt``.
 
 .. raw:: html
 
   <details><summary>TODO 6: Click to show/hide answer</summary>
 
-.. code-block:: c++
-  :caption: TODO 6 : tutorial.cxx
-  :name: tutorial.cxx-call_mysqrt
-
-  const double outputValue = mysqrt(inputValue);
+.. literalinclude:: Step3/tutorial.cxx
+  :caption: TODO 7: tutorial.cxx
+  :name: CMakeLists.txt-option
+  :language: cmake
+  :start-after:   const double inputValue = std::stod(argv[1]);
+  :end-before: std::cout
 
 .. raw:: html
 
   </details>
 
-Exercise 2 - Making Our Library Optional
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Exercise 2 - Adding an Option
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Now let us make the MathFunctions library optional. While for the tutorial
+Now let us add an option in the MathFunctions library to allow developers to
+select either the custom square root implementation or the built in standard
+implementation. While for the tutorial
 there really isn't any need to do so, for larger projects this is a common
 occurrence.
 
@@ -219,28 +225,26 @@ Helpful Resources
 -----------------
 
 * :command:`if`
-* :command:`list`
 * :command:`option`
-* :command:`cmakedefine <configure_file>`
+* :command:`target_compile_definitions`
 
 Files to Edit
 -------------
 
-* ``CMakeLists.txt``
-* ``tutorial.cxx``
-* ``TutorialConfig.h.in``
+* ``MathFunctions/CMakeLists.txt``
+* ``MathFunctions/MathFunctions.cxx``
 
 Getting Started
 ---------------
 
 Start with the resulting files from Exercise 1. Complete ``TODO 7`` through
-``TODO 13``.
+``TODO 9``.
 
 First create a variable ``USE_MYMATH`` using the :command:`option` command
-in the top-level ``CMakeLists.txt`` file. In that same file, use that option
-to determine whether to build and use the ``MathFunctions`` library.
+in ``MathFunctions/CMakeLists.txt``. In that same file, use that option
+to pass a compile definition to the ``MathFunctions`` library.
 
-Then, update ``tutorial.cxx`` and ``TutorialConfig.h.in`` to use
+Then, update ``MathFunctions.cxx`` to redirect compilation based on
 ``USE_MYMATH``.
 
 Build and Run
@@ -279,7 +283,7 @@ or ``mysqrt``?
 Solution
 --------
 
-The first step is to add an option to the top-level ``CMakeLists.txt`` file.
+The first step is to add an option to ``MathFunctions/CMakeLists.txt``.
 This option will be displayed in the :manual:`cmake-gui <cmake-gui(1)>` and
 :manual:`ccmake <ccmake(1)>` with a default value of ``ON`` that can be
 changed by the user.
@@ -288,172 +292,95 @@ changed by the user.
 
   <details><summary>TODO 7: Click to show/hide answer</summary>
 
-.. literalinclude:: Step3/CMakeLists.txt
-  :caption: TODO 7: CMakeLists.txt
-  :name: CMakeLists.txt-option
+.. literalinclude:: Step3/MathFunctions/CMakeLists.txt
+  :caption: TODO 7: MathFunctions/CMakeLists.txt
+  :name: CMakeLists.txt-option-library-level
   :language: cmake
   :start-after: # should we use our own math functions
-  :end-before: # configure a header file to pass some of the CMake settings
+  :end-before: if (USE_MYMATH)
 
 .. raw:: html
 
   </details>
 
-Next, make building and linking the ``MathFunctions`` library
-conditional.
-
-Start by creating a :command:`list` of the optional library targets for our
-project. At the moment, it is just ``MathFunctions``. Let's name our list
-``EXTRA_LIBS``.
+Next, make building and linking our library with ``mysqrt`` function
+conditional using this new option.
 
-Similarly, we need to make a :command:`list` for the optional includes which
-we will call ``EXTRA_INCLUDES``. In this list, we will ``APPEND`` the path of
-the header file needed for our library.
-
-Next, create an :command:`if` statement which checks the value of
+Create an :command:`if` statement which checks the value of
 ``USE_MYMATH``. Inside the :command:`if` block, put the
-:command:`add_subdirectory` command from Exercise 1 with the additional
-:command:`list` commands.
-
-When ``USE_MYMATH`` is ``ON``, the lists will be generated and will be added to
-our project. When ``USE_MYMATH`` is ``OFF``, the lists stay empty. With this
-strategy, we allow users to toggle ``USE_MYMATH`` to manipulate what library is
-used in the build.
-
-The top-level CMakeLists.txt file will now look like the following:
+:command:`target_compile_definitions` command with the compile
+definition ``USE_MYMATH``.
 
 .. raw:: html
 
   <details><summary>TODO 8: Click to show/hide answer</summary>
 
-.. literalinclude:: Step3/CMakeLists.txt
-  :caption: TODO 8: CMakeLists.txt
+.. literalinclude:: Step3/MathFunctions/CMakeLists.txt
+  :caption: TODO 8: MathFunctions/CMakeLists.txt
   :name: CMakeLists.txt-USE_MYMATH
   :language: cmake
-  :start-after: # add the MathFunctions library
-  :end-before: # add the executable
+  :start-after: USE_MYMATH "Use tutorial provided math implementation" ON)
 
 .. raw:: html
 
   </details>
 
-Now that we have these two lists, we need to update
-:command:`target_link_libraries` and :command:`target_include_directories` to
-use them. Changing them is fairly straightforward.
-
-For :command:`target_link_libraries`, we replace the written out
-library names with ``EXTRA_LIBS``. This looks like the following:
+The corresponding changes to the source code are fairly straightforward.
+In ``MathFunctions.cxx``, we make ``USE_MYMATH`` control which square root
+function is used:
 
 .. raw:: html
 
   <details><summary>TODO 9: Click to show/hide answer</summary>
 
-.. literalinclude:: Step3/CMakeLists.txt
-  :caption: TODO 9: CMakeLists.txt
-  :name: CMakeLists.txt-target_link_libraries-EXTRA_LIBS
-  :language: cmake
-  :start-after: add_executable(Tutorial tutorial.cxx)
-  :end-before: # TODO 3
+.. literalinclude:: Step3/MathFunctions/MathFunctions.cxx
+  :caption: TODO 9: MathFunctions/MathFunctions.cxx
+  :name: MathFunctions-USE_MYMATH-if
+  :language: c++
+  :start-after: which square root function should we use?
+  :end-before: }
 
 .. raw:: html
 
   </details>
 
-Then, we do the same thing with :command:`target_include_directories` and
-``EXTRA_INCLUDES``.
+Next, we need to include ``mysqrt.h`` if ``USE_MYMATH`` is defined.
 
 .. raw:: html
 
   <details><summary>TODO 10: Click to show/hide answer</summary>
 
-.. literalinclude:: Step3/CMakeLists.txt
-  :caption: TODO 10 : CMakeLists.txt
-  :name: CMakeLists.txt-target_link_libraries-EXTRA_INCLUDES
-  :language: cmake
-  :start-after: # so that we will find TutorialConfig.h
-
-.. raw:: html
-
-  </details>
-
-Note that this is a classic approach when dealing with many components. We
-will cover the modern approach in the Step 3 of the tutorial.
-
-The corresponding changes to the source code are fairly straightforward.
-First, in ``tutorial.cxx``, we include the ``MathFunctions.h`` header if
-``USE_MYMATH`` is defined.
-
-.. raw:: html
-
-  <details><summary>TODO 11: Click to show/hide answer</summary>
-
-.. literalinclude:: Step3/tutorial.cxx
-  :caption: TODO 11 : tutorial.cxx
-  :name: tutorial.cxx-ifdef-include
+.. literalinclude:: Step3/MathFunctions/MathFunctions.cxx
+  :caption: TODO 10: MathFunctions/MathFunctions.cxx
+  :name: MathFunctions-USE_MYMATH-if-include
   :language: c++
-  :start-after: // should we include the MathFunctions header
-  :end-before: int main
+  :start-after: include <cmath>
+  :end-before: namespace mathfunctions
 
 .. raw:: html
 
   </details>
 
-Then, in the same file, we make ``USE_MYMATH`` control which square root
-function is used:
-
-.. raw:: html
-
-  <details><summary>TODO 12: Click to show/hide answer</summary>
-
-.. literalinclude:: Step3/tutorial.cxx
-  :caption: TODO 12 : tutorial.cxx
-  :name: tutorial.cxx-ifdef-const
-  :language: c++
-  :start-after: // which square root function should we use?
-  :end-before: std::cout << "The square root of
+Finally, we need to include ``cmath`` now that we are using ``std::sqrt``.
 
 .. raw:: html
 
-  </details>
-
-Since the source code now requires ``USE_MYMATH`` we can add it to
-``TutorialConfig.h.in`` with the following line:
-
-.. raw:: html
+  <details><summary>TODO 11: Click to show/hide answer</summary>
 
-  <details><summary>TODO 13: Click to show/hide answer</summary>
+.. code-block:: c++
+  :caption: TODO 11 : MathFunctions/MathFunctions.cxx
+  :name: tutorial.cxx-include_cmath
 
-.. literalinclude:: Step3/TutorialConfig.h.in
-  :caption: TODO 13 : TutorialConfig.h.in
-  :name: TutorialConfig.h.in-cmakedefine
-  :language: c++
-  :lines: 4
+  #include <cmath>
 
 .. raw:: html
 
   </details>
 
-With these changes, our library is now completely optional to whoever is
-building and using it.
-
-Bonus Question
---------------
-
-Why is it important that we configure ``TutorialConfig.h.in``
-after the option for ``USE_MYMATH``? What would happen if we inverted the two?
-
-Answer
-------
+When ``USE_MYMATH`` is ``ON``, the compile definition ``USE_MYMATH`` will
+be set. We can then use this compile definition to enable or disable
+sections of our source code. With this strategy, we allow users to
+toggle ``USE_MYMATH`` to manipulate what library is used in the build.
 
-.. raw:: html
-
-  <details><summary>Click to show/hide answer</summary>
-
-We configure after because ``TutorialConfig.h.in`` uses the value of
-``USE_MYMATH``. If we configure the file before
-calling :command:`option`, we won't be using the expected value of
-``USE_MYMATH``.
-
-.. raw:: html
-
-  </details>
+With these changes, the ``mysqrt`` function is now completely optional to
+whoever is building and using the ``MathFunctions`` library.
diff --git a/Help/guide/tutorial/Complete/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Complete/MathFunctions/MathFunctions.cxx
index 0145300629..c0991b9b98 100644
--- a/Help/guide/tutorial/Complete/MathFunctions/MathFunctions.cxx
+++ b/Help/guide/tutorial/Complete/MathFunctions/MathFunctions.cxx
@@ -10,6 +10,7 @@
 namespace mathfunctions {
 double sqrt(double x)
 {
+// which square root function should we use?
 #ifdef USE_MYMATH
   return detail::mysqrt(x);
 #else
diff --git a/Help/guide/tutorial/Selecting Static or Shared Libraries.rst b/Help/guide/tutorial/Selecting Static or Shared Libraries.rst
index 7befe1d3fd..504e42fd58 100644
--- a/Help/guide/tutorial/Selecting Static or Shared Libraries.rst
+++ b/Help/guide/tutorial/Selecting Static or Shared Libraries.rst
@@ -10,49 +10,22 @@ To accomplish this we need to add :variable:`BUILD_SHARED_LIBS` to the
 top-level ``CMakeLists.txt``. We use the :command:`option` command as it allows
 users to optionally select if the value should be ``ON`` or ``OFF``.
 
-Next we are going to refactor ``MathFunctions`` to become a real library that
-encapsulates using ``mysqrt`` or ``sqrt``, instead of requiring the calling
-code to do this logic. This will also mean that ``USE_MYMATH`` will not control
-building ``MathFunctions``, but instead will control the behavior of this
-library.
-
-The first step is to update the starting section of the top-level
-``CMakeLists.txt`` to look like:
-
 .. literalinclude:: Step11/CMakeLists.txt
   :caption: CMakeLists.txt
   :name: CMakeLists.txt-option-BUILD_SHARED_LIBS
   :language: cmake
-  :end-before: # add the binary tree
-
-Now that we have made ``MathFunctions`` always be used, we will need to update
-the logic of that library. So, in ``MathFunctions/CMakeLists.txt`` we need to
-create a SqrtLibrary that will conditionally be built and installed when
-``USE_MYMATH`` is enabled. Now, since this is a tutorial, we are going to
-explicitly require that SqrtLibrary is built statically.
+  :start-after: set(CMAKE_RUNTIME_OUTPUT_DIRECTORY
+  :end-before: # configure a header file to pass the version number only
 
-The end result is that ``MathFunctions/CMakeLists.txt`` should look like:
+Next, we need to specify output directories for our static and shared
+libraries.
 
-.. literalinclude:: Step11/MathFunctions/CMakeLists.txt
-  :caption: MathFunctions/CMakeLists.txt
-  :name: MathFunctions/CMakeLists.txt-add_library-STATIC
+.. literalinclude:: Step11/CMakeLists.txt
+  :caption: CMakeLists.txt
+  :name: CMakeLists.txt-cmake-output-directories
   :language: cmake
-  :lines: 1-36,42-
-
-Next, update ``MathFunctions/mysqrt.cxx`` to use the ``mathfunctions`` and
-``detail`` namespaces:
-
-.. literalinclude:: Step11/MathFunctions/mysqrt.cxx
-  :caption: MathFunctions/mysqrt.cxx
-  :name: MathFunctions/mysqrt.cxx-namespace
-  :language: c++
-
-We also need to make some changes in ``tutorial.cxx``, so that it no longer
-uses ``USE_MYMATH``:
-
-#. Always include ``MathFunctions.h``
-#. Always use ``mathfunctions::sqrt``
-#. Don't include ``cmath``
+  :start-after: # we don't need to tinker with the path to run the executable
+  :end-before: # configure a header file to pass the version number only
 
 Finally, update ``MathFunctions/MathFunctions.h`` to use dll export defines:
 
diff --git a/Help/guide/tutorial/Step10/CMakeLists.txt b/Help/guide/tutorial/Step10/CMakeLists.txt
index 5c661aa229..2dd6db50f9 100644
--- a/Help/guide/tutorial/Step10/CMakeLists.txt
+++ b/Help/guide/tutorial/Step10/CMakeLists.txt
@@ -16,22 +16,15 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
-# configure a header file to pass some of the CMake settings
-# to the source code
+# configure a header file to pass the version number only
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt
index fa73321670..6f6c430cec 100644
--- a/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt
@@ -1,32 +1,51 @@
-# first we add the executable that generates the table
-add_executable(MakeTable MakeTable.cxx)
-
-# add the command to generate the source code
-add_custom_command(
-  OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  DEPENDS MakeTable
-  )
-
-# add the main library
-add_library(MathFunctions
-            mysqrt.cxx
-            ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-            )
+# add the library that runs
+add_library(MathFunctions MathFunctions.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
-# state that we depend on our binary dir to find Table.h
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          PRIVATE   ${CMAKE_CURRENT_BINARY_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
-# link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if(USE_MYMATH)
+
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # first we add the executable that generates the table
+  add_executable(MakeTable MakeTable.cxx)
+  target_link_libraries(MakeTable PRIVATE tutorial_compiler_flags)
+
+  # add the command to generate the source code
+  add_custom_command(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+    COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+    DEPENDS MakeTable
+    )
+
+  # library that just does sqrt
+  add_library(SqrtLibrary STATIC
+              mysqrt.cxx
+              ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+              )
+
+  # state that we depend on our binary dir to find Table.h
+  target_include_directories(SqrtLibrary PRIVATE
+                             ${CMAKE_CURRENT_BINARY_DIR}
+                             )
+
+  target_link_libraries(SqrtLibrary PUBLIC tutorial_compiler_flags)
+  target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
+endif()
+
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
+if(TARGET SqrtLibrary)
+  list(APPEND installable_libs SqrtLibrary)
+endif()
 install(TARGETS ${installable_libs} DESTINATION lib)
 # install include headers
 install(FILES MathFunctions.h DESTINATION include)
diff --git a/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.cxx
index 0145300629..c0991b9b98 100644
--- a/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.cxx
+++ b/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.cxx
@@ -10,6 +10,7 @@
 namespace mathfunctions {
 double sqrt(double x)
 {
+// which square root function should we use?
 #ifdef USE_MYMATH
   return detail::mysqrt(x);
 #else
diff --git a/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.h
index cd36bccffd..1e916e1192 100644
--- a/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step10/MathFunctions/MathFunctions.h
@@ -1 +1,3 @@
-double mysqrt(double x);
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx
index 7d80ee9648..8153f18bed 100644
--- a/Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx
@@ -5,6 +5,8 @@
 // include the generated table
 #include "Table.h"
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -31,3 +33,5 @@ double mysqrt(double x)
 
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step10/TutorialConfig.h.in b/Help/guide/tutorial/Step10/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step10/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step10/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step10/tutorial.cxx b/Help/guide/tutorial/Step10/tutorial.cxx
index b3c6a4f43c..37a03336ca 100644
--- a/Help/guide/tutorial/Step10/tutorial.cxx
+++ b/Help/guide/tutorial/Step10/tutorial.cxx
@@ -1,15 +1,11 @@
 // A simple program that computes the square root of a number
-#include <cmath>
 #include <iostream>
+#include <sstream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step11/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step11/MathFunctions/MathFunctions.cxx
index 0145300629..c0991b9b98 100644
--- a/Help/guide/tutorial/Step11/MathFunctions/MathFunctions.cxx
+++ b/Help/guide/tutorial/Step11/MathFunctions/MathFunctions.cxx
@@ -10,6 +10,7 @@
 namespace mathfunctions {
 double sqrt(double x)
 {
+// which square root function should we use?
 #ifdef USE_MYMATH
   return detail::mysqrt(x);
 #else
diff --git a/Help/guide/tutorial/Step12/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step12/MathFunctions/MathFunctions.cxx
index 0145300629..c0991b9b98 100644
--- a/Help/guide/tutorial/Step12/MathFunctions/MathFunctions.cxx
+++ b/Help/guide/tutorial/Step12/MathFunctions/MathFunctions.cxx
@@ -10,6 +10,7 @@
 namespace mathfunctions {
 double sqrt(double x)
 {
+// which square root function should we use?
 #ifdef USE_MYMATH
   return detail::mysqrt(x);
 #else
diff --git a/Help/guide/tutorial/Step2/CMakeLists.txt b/Help/guide/tutorial/Step2/CMakeLists.txt
index 2b96128e16..0a06ed7d49 100644
--- a/Help/guide/tutorial/Step2/CMakeLists.txt
+++ b/Help/guide/tutorial/Step2/CMakeLists.txt
@@ -7,36 +7,20 @@ project(Tutorial VERSION 1.0)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 
-# TODO 7: Create a variable USE_MYMATH using option and set default to ON
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
-# TODO 8: Use list() and APPEND to create a list of optional libraries
-# called  EXTRA_LIBS and a list of optional include directories called
-# EXTRA_INCLUDES. Add the MathFunctions library and source directory to
-# the appropriate lists.
-#
-# Only call add_subdirectory and only add MathFunctions specific values
-# to EXTRA_LIBS and EXTRA_INCLUDES if USE_MYMATH is true.
-
 # TODO 2: Use add_subdirectory() to add MathFunctions to this project
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
 
-# TODO 9: Use EXTRA_LIBS instead of the MathFunctions specific values
-# in target_link_libraries.
-
 # TODO 3: Use target_link_libraries to link the library to our executable
 
 # TODO 4: Add MathFunctions to Tutorial's target_include_directories()
 # Hint: ${PROJECT_SOURCE_DIR} is a path to the project source. AKA This folder!
 
-# TODO 10: Use EXTRA_INCLUDES instead of the MathFunctions specific values
-# in target_include_directories.
-
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
 target_include_directories(Tutorial PUBLIC
diff --git a/Help/guide/tutorial/Step2/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step2/MathFunctions/CMakeLists.txt
index b7779b7f28..c468b0e304 100644
--- a/Help/guide/tutorial/Step2/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step2/MathFunctions/CMakeLists.txt
@@ -1,2 +1,7 @@
 # TODO 1: Add a library called MathFunctions
 # Hint: You will need the add_library command
+
+# TODO 7: Create a variable USE_MYMATH using option and set default to ON
+
+# TODO 8: If USE_MYMATH is ON, use target_compile_definitions to pass
+# USE_MYMATH as a precompiled definition to our source files
diff --git a/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..781d0ecc4e
--- /dev/null
+++ b/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,15 @@
+#include "MathFunctions.h"
+
+// TODO 11: include cmath
+
+// TODO 10: Wrap the mysqrt include in a precompiled ifdef based on USE_MYMATH
+#include "mysqrt.h"
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+  // TODO 9: If USE_MYMATH is defined, use detail::mysqrt.
+  // Otherwise, use std::sqrt.
+  return detail::mysqrt(x);
+}
+}
diff --git a/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step2/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step2/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step2/MathFunctions/mysqrt.cxx
index 1e4d97ae7c..ba0ac645b5 100644
--- a/Help/guide/tutorial/Step2/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step2/MathFunctions/mysqrt.cxx
@@ -1,5 +1,9 @@
+#include "mysqrt.h"
+
 #include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -20,3 +24,5 @@ double mysqrt(double x)
   }
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step2/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step2/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step2/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step2/TutorialConfig.h.in b/Help/guide/tutorial/Step2/TutorialConfig.h.in
index 6c09e1aca4..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step2/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step2/TutorialConfig.h.in
@@ -1,5 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-
-// TODO 13: use cmakedefine to define USE_MYMATH
diff --git a/Help/guide/tutorial/Step2/tutorial.cxx b/Help/guide/tutorial/Step2/tutorial.cxx
index 87f5e0f645..7a2a5951e6 100644
--- a/Help/guide/tutorial/Step2/tutorial.cxx
+++ b/Help/guide/tutorial/Step2/tutorial.cxx
@@ -3,11 +3,8 @@
 #include <iostream>
 #include <string>
 
-#include "TutorialConfig.h"
-
-// TODO 11: Only include MathFunctions if USE_MYMATH is defined
-
 // TODO 5: Include MathFunctions.h
+#include "TutorialConfig.h"
 
 int main(int argc, char* argv[])
 {
@@ -22,9 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // TODO 12: Use mysqrt if USE_MYMATH is defined and sqrt otherwise
-
-  // TODO 6: Replace sqrt with mysqrt
+  // TODO 6: Replace sqrt with mathfunctions::sqrt
 
   // calculate square root
   const double outputValue = sqrt(inputValue);
diff --git a/Help/guide/tutorial/Step3/CMakeLists.txt b/Help/guide/tutorial/Step3/CMakeLists.txt
index 007770a373..f051826a7d 100644
--- a/Help/guide/tutorial/Step3/CMakeLists.txt
+++ b/Help/guide/tutorial/Step3/CMakeLists.txt
@@ -7,9 +7,6 @@ project(Tutorial VERSION 1.0)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
@@ -17,16 +14,13 @@ configure_file(TutorialConfig.h.in TutorialConfig.h)
 # TODO 2: Remove EXTRA_INCLUDES list
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-  list(APPEND EXTRA_INCLUDES "${PROJECT_SOURCE_DIR}/MathFunctions")
-endif()
+add_subdirectory(MathFunctions)
+list(APPEND EXTRA_INCLUDES "${PROJECT_SOURCE_DIR}/MathFunctions")
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
 
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS})
+target_link_libraries(Tutorial PUBLIC MathFunctions)
 
 # TODO 3: Remove use of EXTRA_INCLUDES
 
diff --git a/Help/guide/tutorial/Step3/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step3/MathFunctions/CMakeLists.txt
index 7bf05e02c5..90d6c24958 100644
--- a/Help/guide/tutorial/Step3/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step3/MathFunctions/CMakeLists.txt
@@ -1,5 +1,11 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
 
 # TODO 1: State that anybody linking to MathFunctions needs to include the
 # current source directory, while MathFunctions itself doesn't.
 # Hint: Use target_include_directories with the INTERFACE keyword
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+endif()
diff --git a/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step3/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step3/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step3/MathFunctions/mysqrt.cxx
index abe767d5ae..ba0ac645b5 100644
--- a/Help/guide/tutorial/Step3/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step3/MathFunctions/mysqrt.cxx
@@ -1,7 +1,9 @@
-#include <iostream>
+#include "mysqrt.h"
 
-#include "MathFunctions.h"
+#include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -22,3 +24,5 @@ double mysqrt(double x)
   }
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step3/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step3/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step3/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step3/TutorialConfig.h.in b/Help/guide/tutorial/Step3/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step3/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step3/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step3/tutorial.cxx b/Help/guide/tutorial/Step3/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step3/tutorial.cxx
+++ b/Help/guide/tutorial/Step3/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step4/CMakeLists.txt b/Help/guide/tutorial/Step4/CMakeLists.txt
index fa4aab270b..dcda1359f4 100644
--- a/Help/guide/tutorial/Step4/CMakeLists.txt
+++ b/Help/guide/tutorial/Step4/CMakeLists.txt
@@ -31,25 +31,19 @@ set(CMAKE_CXX_STANDARD_REQUIRED True)
 # build-tree
 # Hint: Use BUILD_INTERFACE
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
 
 # TODO 2: Link to tutorial_compiler_flags
 
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS})
+target_link_libraries(Tutorial PUBLIC MathFunctions)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step4/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step4/MathFunctions/CMakeLists.txt
index 5f7369cae7..cc71d8600a 100644
--- a/Help/guide/tutorial/Step4/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step4/MathFunctions/CMakeLists.txt
@@ -1,9 +1,15 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+endif()
 
 # TODO 3: Link to tutorial_compiler_flags
diff --git a/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step4/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step4/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step4/MathFunctions/mysqrt.cxx
index abe767d5ae..ba0ac645b5 100644
--- a/Help/guide/tutorial/Step4/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step4/MathFunctions/mysqrt.cxx
@@ -1,7 +1,9 @@
-#include <iostream>
+#include "mysqrt.h"
 
-#include "MathFunctions.h"
+#include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -22,3 +24,5 @@ double mysqrt(double x)
   }
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step4/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step4/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step4/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step4/TutorialConfig.h.in b/Help/guide/tutorial/Step4/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step4/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step4/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step4/tutorial.cxx b/Help/guide/tutorial/Step4/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step4/tutorial.cxx
+++ b/Help/guide/tutorial/Step4/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step5/CMakeLists.txt b/Help/guide/tutorial/Step5/CMakeLists.txt
index 279ddf93a3..ad814f69eb 100644
--- a/Help/guide/tutorial/Step5/CMakeLists.txt
+++ b/Help/guide/tutorial/Step5/CMakeLists.txt
@@ -16,22 +16,17 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt
index 6cd88d7ec2..000a786ed6 100644
--- a/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt
@@ -1,13 +1,19 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+endif()
 
 # link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # TODO 1: Create a variable called installable_libs that is a list of all
 # libraries we want to install (e.g. MathFunctions and tutorial_compiler_flags)
diff --git a/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step5/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx
index abe767d5ae..ba0ac645b5 100644
--- a/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx
@@ -1,7 +1,9 @@
-#include <iostream>
+#include "mysqrt.h"
 
-#include "MathFunctions.h"
+#include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -22,3 +24,5 @@ double mysqrt(double x)
   }
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step5/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step5/TutorialConfig.h.in b/Help/guide/tutorial/Step5/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step5/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step5/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step5/tutorial.cxx b/Help/guide/tutorial/Step5/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step5/tutorial.cxx
+++ b/Help/guide/tutorial/Step5/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step6/CMakeLists.txt b/Help/guide/tutorial/Step6/CMakeLists.txt
index c11e307736..a86d60aae0 100644
--- a/Help/guide/tutorial/Step6/CMakeLists.txt
+++ b/Help/guide/tutorial/Step6/CMakeLists.txt
@@ -16,22 +16,17 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt
index b4724c4a10..623cb742f8 100644
--- a/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt
@@ -1,13 +1,19 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+endif()
 
 # link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
diff --git a/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step6/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step6/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step6/MathFunctions/mysqrt.cxx
index abe767d5ae..ba0ac645b5 100644
--- a/Help/guide/tutorial/Step6/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step6/MathFunctions/mysqrt.cxx
@@ -1,7 +1,9 @@
-#include <iostream>
+#include "mysqrt.h"
 
-#include "MathFunctions.h"
+#include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -22,3 +24,5 @@ double mysqrt(double x)
   }
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step6/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step6/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step6/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step6/TutorialConfig.h.in b/Help/guide/tutorial/Step6/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step6/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step6/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step6/tutorial.cxx b/Help/guide/tutorial/Step6/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step6/tutorial.cxx
+++ b/Help/guide/tutorial/Step6/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step7/CMakeLists.txt b/Help/guide/tutorial/Step7/CMakeLists.txt
index d26a90cee8..97ec6aaa38 100644
--- a/Help/guide/tutorial/Step7/CMakeLists.txt
+++ b/Help/guide/tutorial/Step7/CMakeLists.txt
@@ -16,22 +16,17 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt
index e5bdc4da15..c0d1e72912 100644
--- a/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt
@@ -1,33 +1,39 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
-# link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # TODO 1: Include CheckCXXSourceCompiles
 
-# TODO 1: Include CheckCXXSourceCompiles
+  # TODO 2: Use check_cxx_source_compiles with simple C++ code to verify
+  # availability of:
+  # * std::log
+  # * std::exp
+  # Store the results in HAVE_LOG and HAVE_EXP respectively.
 
-# TODO 2: Use check_cxx_source_compiles with simple C++ code to verify
-# availability of:
-# * std::log
-# * std::exp
-# Store the results in HAVE_LOG and HAVE_EXP respectively.
+  # Hint: Sample C++ code which uses log:
+  # #include <cmath>
+  # int main() {
+  #   std::log(1.0);
+  #   return 0;
+  # }
 
-# Hint: Sample C++ code which uses log:
-# #include <cmath>
-# int main() {
-#   std::log(1.0);
-#   return 0;
-# }
+  # TODO 3: Conditionally on HAVE_LOG and HAVE_EXP, add private compile
+  # definitions "HAVE_LOG" and "HAVE_EXP" to the MathFunctions target.
 
-# TODO 3: Conditionally on HAVE_LOG and HAVE_EXP, add private compile
-# definitions "HAVE_LOG" and "HAVE_EXP" to the MathFunctions target.
+  # Hint: Use target_compile_definitions()
+endif()
 
-#Hint: Use target_compile_definitions()
+# link our compiler flags interface library
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
diff --git a/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step7/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step7/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step7/MathFunctions/mysqrt.cxx
index 3d2492a648..9963cff7dc 100644
--- a/Help/guide/tutorial/Step7/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step7/MathFunctions/mysqrt.cxx
@@ -1,8 +1,9 @@
-#include <iostream>
+#include "mysqrt.h"
 
-// TODO 4: include cmath
-#include "MathFunctions.h"
+#include <iostream>
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -32,3 +33,5 @@ double mysqrt(double x)
 
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step7/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step7/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step7/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step7/TutorialConfig.h.in b/Help/guide/tutorial/Step7/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step7/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step7/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step7/tutorial.cxx b/Help/guide/tutorial/Step7/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step7/tutorial.cxx
+++ b/Help/guide/tutorial/Step7/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step8/CMakeLists.txt b/Help/guide/tutorial/Step8/CMakeLists.txt
index cb87281b9e..97ec6aaa38 100644
--- a/Help/guide/tutorial/Step8/CMakeLists.txt
+++ b/Help/guide/tutorial/Step8/CMakeLists.txt
@@ -16,23 +16,17 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
index f81b563409..861014ddc1 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
@@ -1,36 +1,43 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # does this system provide the log and exp functions?
+  include(CheckCXXSourceCompiles)
+  check_cxx_source_compiles("
+    #include <cmath>
+    int main() {
+      std::log(1.0);
+      return 0;
+    }
+  " HAVE_LOG)
+  check_cxx_source_compiles("
+    #include <cmath>
+    int main() {
+      std::exp(1.0);
+      return 0;
+    }
+  " HAVE_EXP)
+
+  # add compile definitions
+  if(HAVE_LOG AND HAVE_EXP)
+    target_compile_definitions(MathFunctions
+                               PRIVATE "HAVE_LOG" "HAVE_EXP"
+                               )
+  endif()
+endif()
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
 # link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
-
-# does this system provide the log and exp functions?
-include(CheckCXXSourceCompiles)
-check_cxx_source_compiles("
-  #include <cmath>
-  int main() {
-    std::log(1.0);
-    return 0;
-  }
-" HAVE_LOG)
-check_cxx_source_compiles("
-  #include <cmath>
-  int main() {
-    std::exp(1.0);
-    return 0;
-  }
-" HAVE_EXP)
-
-# add compile definitions
-if(HAVE_LOG AND HAVE_EXP)
-  target_compile_definitions(MathFunctions
-                             PRIVATE "HAVE_LOG" "HAVE_EXP")
-endif()
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
diff --git a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
index 7eecd26b5d..28ab042de6 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
@@ -1,8 +1,10 @@
+#include "mysqrt.h"
+
 #include <cmath>
 #include <iostream>
 
-#include "MathFunctions.h"
-
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -30,3 +32,5 @@ double mysqrt(double x)
 #endif
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step8/TutorialConfig.h.in b/Help/guide/tutorial/Step8/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step8/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step8/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step8/tutorial.cxx b/Help/guide/tutorial/Step8/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step8/tutorial.cxx
+++ b/Help/guide/tutorial/Step8/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;
diff --git a/Help/guide/tutorial/Step9/CMakeLists.txt b/Help/guide/tutorial/Step9/CMakeLists.txt
index d26a90cee8..97ec6aaa38 100644
--- a/Help/guide/tutorial/Step9/CMakeLists.txt
+++ b/Help/guide/tutorial/Step9/CMakeLists.txt
@@ -16,22 +16,17 @@ target_compile_options(tutorial_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
 )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-
 # configure a header file to pass some of the CMake settings
 # to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-if(USE_MYMATH)
-  add_subdirectory(MathFunctions)
-  list(APPEND EXTRA_LIBS MathFunctions)
-endif()
+add_subdirectory(MathFunctions)
 
 # add the executable
 add_executable(Tutorial tutorial.cxx)
-target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
+
+target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
diff --git a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
index 8e04f97492..05c86162e4 100644
--- a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
@@ -1,34 +1,49 @@
-# first we add the executable that generates the table
-add_executable(MakeTable MakeTable.cxx)
-
-# add the command to generate the source code
-add_custom_command(
-  OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  DEPENDS MakeTable
-  )
-
-# add the main library
-add_library(MathFunctions
-            mysqrt.cxx
-            ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-            )
+add_library(MathFunctions MathFunctions.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
-# state that we depend on Tutorial_BINARY_DIR but consumers don't, as the
-# TutorialConfig.h include is an implementation detail
-# state that we depend on our binary dir to find Table.h
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          PRIVATE   ${CMAKE_CURRENT_BINARY_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
-# link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # first we add the executable that generates the table
+  add_executable(MakeTable MakeTable.cxx)
+  target_link_libraries(MakeTable PRIVATE tutorial_compiler_flags)
+
+  # add the command to generate the source code
+  add_custom_command(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+    COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+    DEPENDS MakeTable
+    )
+
+  # library that just does sqrt
+  add_library(SqrtLibrary STATIC
+              mysqrt.cxx
+              ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+              )
+
+  # state that we depend on our binary dir to find Table.h
+  target_include_directories(SqrtLibrary PRIVATE
+              ${CMAKE_CURRENT_BINARY_DIR}
+              )
+
+  target_link_libraries(SqrtLibrary PUBLIC tutorial_compiler_flags)
+  target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
+endif()
+
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
+if(TARGET SqrtLibrary)
+  list(APPEND installable_libs SqrtLibrary)
+endif()
 install(TARGETS ${installable_libs} DESTINATION lib)
 # install include headers
 install(FILES MathFunctions.h DESTINATION include)
diff --git a/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000000..dc28b4b530
--- /dev/null
+++ b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h
index cd36bccffd..d5c2f224bf 100644
--- a/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx
index 7d80ee9648..477d715205 100644
--- a/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx
@@ -1,10 +1,12 @@
-#include <iostream>
+#include "mysqrt.h"
 
-#include "MathFunctions.h"
+#include <iostream>
 
 // include the generated table
 #include "Table.h"
 
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -31,3 +33,5 @@ double mysqrt(double x)
 
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h
new file mode 100644
index 0000000000..593d41e7a6
--- /dev/null
+++ b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}
diff --git a/Help/guide/tutorial/Step9/TutorialConfig.h.in b/Help/guide/tutorial/Step9/TutorialConfig.h.in
index e23f5213c7..7e4d7fa1fa 100644
--- a/Help/guide/tutorial/Step9/TutorialConfig.h.in
+++ b/Help/guide/tutorial/Step9/TutorialConfig.h.in
@@ -1,4 +1,3 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
-#cmakedefine USE_MYMATH
diff --git a/Help/guide/tutorial/Step9/tutorial.cxx b/Help/guide/tutorial/Step9/tutorial.cxx
index b3c6a4f43c..a3a2bdce00 100644
--- a/Help/guide/tutorial/Step9/tutorial.cxx
+++ b/Help/guide/tutorial/Step9/tutorial.cxx
@@ -3,13 +3,9 @@
 #include <iostream>
 #include <string>
 
+#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
-// should we include the MathFunctions header?
-#ifdef USE_MYMATH
-#  include "MathFunctions.h"
-#endif
-
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -23,12 +19,7 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  // which square root function should we use?
-#ifdef USE_MYMATH
-  const double outputValue = mysqrt(inputValue);
-#else
-  const double outputValue = sqrt(inputValue);
-#endif
+  const double outputValue = mathfunctions::sqrt(inputValue);
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;