Premise: Don Quixote is listed in the Appendix, but I could not find him in the dictionary, nor could I find quixotic, Queen of Sheba, Jeeves, Venus, Einstein (for `genius'), Hitler (for `demagogue, tryant'), Attila the Hun (for `barbarian'), Robinson Crusoe (for `castaway; lonely person')'but man Friday is in' Horatio Alger, Narcissus , etc.

Hypothesis: Dictionaries can have flaws and be missing terms. 
Relation: entailment