Traditional macro recursion

[Neil Booth]

Zack, I remember you had an example of a traditional macro
expansion including the macro name but that didn't recurse.
I kind find it any more; I recall it as being one of the ISO
tests in the testsuite though.  Could you remind me what it
was?  I'm trying to come up with a foolproof way of detecting
recursion without waiting till the 200th expansion to find out.

Thanks,

Neil.