Don't be spook'ed by the math signs,
For they're the key to find the line...
I don't think it's this, but is it
de- for less which also sounds like the
the second part might mean ray ven which is raven.
Since it is literature, I think it might be The Raven by Edgar Allan Poe.
SteveV has suggested that it might include
Quote which might be Quoth (the Raven) or maybe nevermore due to the nature of the inequality