The Fool's Function

I first realized that the Fool had disappeared in Dover. Until then he had stuck with King Lear and provided him with cryptic advice throughout the play. However, in Dover, where King Lear acted the most insane, the Fool was no where to be found. The Fool may have disappeared in Dover because he could no longer help King Lear, who by that point had almost completely lost touch with reality. His advice to Lear would have been pointless. Also, the events that took place in Dover were incredibly tragic. The Fool was comical at times throughout the play and his presence during those events may have been inappropriate.
I believe that the Fool's function was to provide Lear with useful advice throughout the play and to entertain the audience with his lengthy poetic lines.