30.04.2009: Propositional logic (syntax; semantics; models, validity, satisfiability, entailment, equivalence; translation to CNF/DNF;
checking unsatisfiability: truth tables, resolution)
7.05.2009: Propositional logic (propositional resolution: soundness and completeness; the DPLL method, part I)
11.05.2009: During the exercise session the following proofs needed in the lecture were presented:
Theorem 1.11. Let FMS(M) be the family of all finite multisets with elements in the set M. Let > be a strict partial order on M, and let >mul be its multiset extension:
>mul is a strict partial order on FMS(M).
if > is total then >mul is total.
if > is well-founded then >mul is well founded.
Proposition 1.12 (i),(ii),(iii)
Theorem 1.14.
A full proof of the model existence theorem (including proofs of
Prop. 1.12) can be found in:
Bachmair, L. and Ganzinger, H.: Resolution Theorem Proving,
Handbook of Automated Reasoning, North Holland, 2001.
[.ps.gz]
14.05.2009: The DPLL method, part II; First-order logic (syntax,
semantics: models and assignments).
28.05.2009: Models, validity, satisfiability; Entailment and equivalence; Validity vs. unsatisfiability; The theory of a structure; Logical theories (syntactic/semantics view); Algorithmic problems; Normal forms and Skolemization; Herbrand interpretations.
4.06.2009: General resolution (resolution for ground clauses,
Robinson's idea; unification, lifting lemma, saturation of sets of general
clauses, Herbrand's theorem, the theorem of Löwenheim-Skolem, refutational
completeness of resolution, ordered resolution with selection, redundancy).
18.06.2009: Undecidability and decidability results: Goedel's theorem (only statement); some decidable fragments for first-order logic without equality (variable-free formulae, the Bernays-Schoenfinkel class, the Ackermann class); tractability (Horn fragments of the above fragments of FOL). Satisfiability w.r.t. a theory (introduction)
25.06.2009: Satisfiability w.r.t. a theory: Convex theories, T-validity vs. T-satisfiability.
Theory of uninterpreted function symbols (motivation, example, Ackermann's reduction)
2.07.2009: Theory of uninterpreted function symbols (optimized satisfiability check using DAGs). Decision procedures for numeric domains: Difference logic (SAT checking expressed as a problem of checking of there are negative cycles in a graph). Survey of methods for reasoning in linear arithmetic, Presburger arithmetic, real numbers. Combinations of theories (introduction).
9.07.2009: The Nelson/Oppen procedure for reasoning in
combinations of theories over disjoint signatures.