Maybe you're just confusing the facts being stated ("even if it were a difficult operation to reverse addition of 3 numbers" implies it is easy, which is true a

Maybe you're just confusing the facts being stated ("even if it were a difficult operation to reverse addition of 3 numbers" implies it is easy, which is true as it's just an oblique restatement of the commutative property) with the language being used. "Difficult", "easier", "even if", etc. I have no idea how sentiment analysis works though.