\"\"

\

The functions are \"f.

\

\"open

\

\"equal                         (Substitute \"\")

\

\"equal                        (Substitute \"\")

\

\"equal

\

\"\"

\

\"open

\

\"equal                       (Substitute \"\")

\

\"equal                        (Substitute \"\")

\

\"equal

\

\"\"

\

\"open so the functions are inverse.