'Deductive Logic' Author Stoked Book Helped Spark Bill Belichick's New Romance

A textbook on logic helped bring Bill Belichick and Jordon Hudson together ... and the man who wrote it tells TMZ Sports he couldn't be happier!!

We broke the story ... the literary piece -- titled "Deductive Logic" -- was what first drew Belichick to Hudson way back in 2021 -- when they had their initial encounter on a plane ride from the Boston area to Florida.

Our sources say the ex-New England Patriots head coach was intrigued by the work that Hudson was studying on the flight ... and sparked up a conversation with her over it all.

We're told the talk led to an autograph, which led to an exchange of numbers -- which ultimately led to the duo dating.

Warren Goldfarb -- the Harvard professor who authored "Deductive Logic" -- said in a message to us on Wednesday he's stoked his work played a role in their love story ... joking, "I'm delighted to see that logic, so often derided as a dry subject, has finally been recognized for its romantic potential!"

We're sure Belichick and Hudson would share similar sentiments ... as the two have been going strong for a while now -- even looking quite smitten at Tom Brady's Patriots Hall of Fame induction ceremony earlier this month.