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2) Prove the following using a Semantic Tableaux. Note: b) can be a long process depending on what formula you choose at each step. Pick alpha before beta, the beta which will most quickly lead to a complementary pair. You may shortcut the algorithm and mark nodes with complementary pairs immediately to save space. and then choose a) H (A B) v (B- C) b) ((A v B) ^ ((A B) ^ (B C))) C