In literature, prolepsis is a type of flashforward, as opposed to a flashback. It is a word or scene that anticipates something to happen in the future.
Two examples occur near the end of the play, Hamlet.
After the fencing challenge is issued and accepted, Horatio says in Act V scene i
You will lose this wager, my lord
even though Hamlet is obviously the better fencer. His assertion indicates that more is going on here than a simple duel; he seems to be flashing forward to the final death scene.
Speaking of the death scene, Hamlet is wounded by the poison-tipped sword. He tells Horatio in scene ii of Act V,
Horatio, I am dead
Again, this is a flashforward. If Hamlet were really dead, he could not be saying this to Horatio.