Completeness ample Given proposition((A→B)→(A→O)→(B→C, there is a truth valuation which make it false. Observe the non-contradictory path of the tableau with the root asF(A→B)→(A→O)→(B→CCompleteness . Example . . Given proposition ((A → B) → (A → C)) → (B → C), there is a truth valuation which make it false. Observe the non-contradictory path of the tableau with the root as F ((A → B) → (A → C)) → (B → C) Yi Li (Fudan University) Discrete Mathematics April 16, 2013 11 / 17