19 lines
722 B
Plaintext
19 lines
722 B
Plaintext
Class 13 : Horn Formulae
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Horn Formulae : CNF with each clause having at most one positive literal.
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Algorithm for satisfiability-greedy algo
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Termination proof
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Time complexity-polytime
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Correctness.
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Soundness : If alogH says formula \alpha is satisfiable then \alpha is satisfiable.
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Proof idea : algoH gives an assignment, we prove that this satisfies \alpha.
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Completeness: If the given formula \alpha is satisfiable then algoH prints "satisfiable".
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Proof idea: Prove the contrapositive of above statement, using the following claim.
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Claim : if a proposition is marked true then it remains true in all
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possible satisfying assignments of the given Horn Formulae
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-- Horn formulae satisfying algorithm and Prolog.
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