Logical Equivelence( Cont Xample a→B≡=aVB Prove by truth table B|-a-aVB F FF FFLogical Equivenlence(Cont.) . Example . .α → β ≡ ¬α ∨ β. . Proof. . . Prove by truth table. α β α → β T T T T F F F T T F F T α β ¬α ¬α ∨ β T T F T T F F F F T T T F F T T Yi Li (Fudan University) Discrete Mathematics April 2, 2013 12 / 20