In Dante's Inferno in Cantos 20 what were the punishments of the diviners,astrologers, and magicians?

n the Fourth Pouch, Dante sees a line of sinners trudging slowly along as if in a church procession. As they pass by the Fourth Pouch, Virgil names several of the sinners here, who were Astrologers, Diviners, or Magicians in life. He explains the punishment of one specific sinner, saying that, since this individual wanted to use unholy powers to see ahead in life (that is, into the future), he has now been condemned to look backward for all of time. Virgil and Dante also see the sorceress Manto there, and Virgil relates a short tale of the founding of Mantua. They then continue on to the Fifth Pouch.