undefining a typedef

[Jose Gomez-Rubio SEED Student]

How does one undefine a typedef construction in a header file?

The problem is that a specific typedef construction is declared
unconditionally in 3 separate header files in a source file that includes
those 3 specific header files.

I've tried #ifndef foobar ... #endif and #if !defined (foobar) ... #endif
to no avail.  The compiler still complains about redefinition of typedef
and refuses to continue.

In the interim, I've commented out the typedef's but I think there is
a better solution.

Thanks for the help!
--
jose at hpsad.hp.com