conjunctive normal form การใช้

• The formula ? is assumed to be in conjunctive normal form.
• Some common normal forms include conjunctive normal form and disjunctive normal form.
• This is a special form of conjunctive normal form.
• Examples of translations involving this concept are Skolemization and some translations into conjunctive normal form.
• Another alternative characterization of positive read-once functions combines their disjunctive and conjunctive normal form.
• To recast the reasoning using the resolution technique, first the clauses must be converted to conjunctive normal form ( CNF ).
• From the negation of the corresponding conditional derive a theorem in conjunctive normal form in the methodical fashions described in text books.
• Typical problems in this case involve formulas in " 3CNF " : conjunctive normal form with no more than three variables per conjunct.
• When a theorem is proven, the system produces a verifiable proof, which validates both the clausification phase and the refutation of the conjunctive normal form.
• A formula in conjunctive normal form hit by a random restriction of the variables can therefore be " switched " to a small formula in disjunctive normal form.
• Further research along the line shows that expert users can use Boolean Conjunctive Normal Form expansion to improve retrieval performance by 50-300 % over unexpanded keyword queries.
• This resolution technique uses proof by contradiction and is based on the fact that any sentence in propositional logic can be transformed into an equivalent sentence in conjunctive normal form.
• The name of the switching lemma stems from the following observation : Take an arbitrary formula in conjunctive normal form, which is in particular a depth-2 circuit.
• The first example is also in conjunctive normal form and the last two are in both conjunctive normal form and disjunctive normal form, but the second example is in neither.
• The first example is also in conjunctive normal form and the last two are in both conjunctive normal form and disjunctive normal form, but the second example is in neither.
• If and only if the original argument was valid will the theorem in conjunctive normal form be a contradiction, and if it is then that it is will be apparent.
• Given that any proposition containing conjunction, disjunction, and negation can be equivalently rephrased using conjunction and negation alone ( the conjunctive normal form ), we can now handle any compound proposition.
• As there exist polynomial-time algorithms to convert any Boolean expression to conjunctive normal form such as Tseitin's algorithm, posing SAT problems in CNF does not change their computational difficulty.
• CNF is the infimum of the numbers ? such that satisfiability of conjunctive normal form formulas without clause length limits can be solved in time O ( 2 ? " n " ).
• Another important NL-complete problem is 2-satisfiability ( Papadimitriou 1994 Thrm . 16.3 ), the problem of determining whether a boolean formula in conjunctive normal form with two variables per clause is satisfiable.