If a > b and b > c then a > c.
IF Karsten Braasch > Serena Williams:
Braasch would smoke cigarettes and sip beer during the changeovers, and to be honest no longer looked the part of a fit professional athlete. It made no matter. Braasch led 5-0 over Serena before winning the set 6-1, and then posted a 6-2 set victory over Venus.
AND Roger Federer (who has spent more than 300 weeks at number one and holds 18 Grand Slam titles) > Karsten Braasch (career best ranking of 38, zero Grand Slams won).
THEN Roger Federer > Serena Williams.
QED.
As a corollary to the above, let us also note that the vast majority of people on Twitter and in the media are big ole dumb dumbs.*
I'd like to thank Alex Griswold for bringing this to my attention. You may all go about your day.
*I'm not sure how to put "big ole dumb dumbs" into a mathematical proof; you'll just have to take my word on that one.