I don't know if y'all review these old posts...

I decided to revisit this problem.  I removed the modifications to NATURAL (i.e. no overrides) and also tried with version 20.05 (with updated alias syntax).  I get the same errors, so these problems have nothing to do with my "modifications of basic classes".

So, if you have time I would really appreciate someone trying to run autotest on feature `is_negative' (using 19.05) and see what I am missing.

I appreciate the work EiffelSoftware does to provide EiffelStudio.  Thanks again.
jjj