- Tautology
- Contradiction
- Entailment-unsatisfiability Duality
- Clause finite set of literals
- Clause Set non-empty set of clauses
- Entailment (Propositional Logic)
- Resolvent
- Resolution
- Definition: Clause set closed under resolution if
- Theorem:
- Construction (1):
- Das sind alle.
- Construction (2):
- Corollary:
- Corollary: is closed
- Corollary:
- Theorems:
- unsatisfiable unsatisfiable
- unsatisfiable
- Theorem:
- Partial interpretation :
- Empty interpretation: (never assigns anything)
- -Interpretation
- If then every is allowed by
- Case: If every :
- Case: not (1) and for all
- Base:
- Recursion step: If is not forbidden by any , then
- we find
- such that all allow
- Case: If all allow
- Case: not (1), all allow =:
- not (1) and not (2)
Appendix