[Doxygen-users] How to document a function that does not exist but has the documentation block?

[Семенов П. <sem...@gm...>]

I want Doxygen to document the code written in C-like language (PARI/GP)
but having slightly different syntax. I believe Doxygen can document the
entities those do not exist. It seems to be the simplest way to do the job
while the programming language is not Doxygen-supported. I want something
like this:

/*!
 \fn foo(param,{option})
 \brief some brief description here
 \param[in](param) mandatory parameter description
 \param[in](option) optional parameter description
*/
/*! \cond DOXYGEN_SHOULD_SKIP_THIS */
foo(param, {option}) =
{
    ...
};
addhelp(foo, "help message for `foo` function");
/*! \endcond */

Unfortunately, Doxygen generates the warning "documented symbol 'foo' was
not declared or defined" and does not list the foo in an output HTML. Is
there any way to force the Doxygen to produce the proper HTML using only
the documentation blocks but not the code?

Thank you very much!

*With best regards, Piotr Semenov*