Hah - I actually started a reply asking about why is ‘a’ equal to 0, implying a disc, as opposed to a ring, but my head hurt, another beer sounded good, and sleep eventually ensued.
Hah - I actually started a reply asking about why is ‘a’ equal to 0, implying a disc, as opposed to a ring, but my head hurt, another beer sounded good, and sleep eventually ensued.