
Which property does Skolemization preserve when converting a first-order formula to Skolem normal form?
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Get StartedWhich property does Skolemization preserve when converting a first-order formula to Skolem normal form?
Options:
- Logical equivalence to the original formula.
- Satisfiability (i.e., equisatisfiability) with respect to the original formula.
- Preservation of all models pointwise.
- Preservation of the formula's free variables only.
Correct answer: Satisfiability (i.e., equisatisfiability) with respect to the original formula.
Explanation: Skolemization yields an equisatisfiable formula: it preserves satisfiability but not full logical equivalence, by replacing existentials with Skolem functions (Skolem, 1920s).
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