Factorial
=========

Save all functions into the same file named ``comb.py``.

#. Write the function :py:func:`factorial` that computes the factorial
   of a given integer. Examples:
   
   .. literalinclude:: test-factorial.txt
         :language: python3
         :lines: 3-

   .. note::
         More tests are provided in file :download:`test-factorial.txt<test-factorial.txt>`
#. Use the preceding function and write the function
   :py:func:`combinatorial` that takes two positive integes *n* and *m*,
   and returns the combinatorial number :math:`{n \choose m} = {n! \over
   {m! (n-m)!}}`. Examples:
   
   .. literalinclude:: test-combinatorial.txt
         :language: python3
         :lines: 3-6

   .. note::
         More tests are provided in file :download:`test-combinatorial.txt<test-combinatorial.txt>`
	 
.. rubric:: Solution

A solution of these functions is provided in the :download:`comb.py <solutions/comb.py>` file.