Hi Dave,

Thanks for updating the results.

My first version of the IndexBitmap class has a bug in the 'insert'
routine. It added values rather than ORed values together. Oops. None
of my tests originally covered this case so it slipped by me.

@documents[ document_symbol ] += (1<<@index.index( word.downcase ))

should be

@documents[ document_symbol ] |= (1<<@index.index( word.downcase ))

Thanks for catching my error where I wasn't checking the mask correctly
in all cases. Again, I lacked a test for this case. Shame. Shame.

Thank you very much for your testing and analysis.

--Dale