Lectures

This page gives highlights of past lectures and provides lecture notes, reading assignments, and exercises.


Dates Topics and Readings Exercises
Jan 19
Jan 21

Course introduction and administration. Introduction to Logic.

Introduction to propositional logic. Syntax and semantics. Parsing and precedence. Interpretations.

Required Readings:

  • Syllabus
  • Introduction slides [pdf]
  • Propositional Logic slides [pdf]
  • Chapter 2 and Sections 3.1-3.2 of LRCS book (available on ICON)
Recommended Material:
  • Moshe Vardi. From Aristotle to the iPhone [talk]
  • Veritasium. Math Has a Fatal Flaw [video essay]

2.3-2.5, 2.9, 2.13, 2.16 of LRCS (Chap. 2)
Jan 24
Jan 26
Jan 28

More on propositional logic. Formula satisfiability, validity, and equivalence. Formula simplification via rewriting. Evaluation of formulas in an interpretation.

From English to propositional logic. Motivation and issues. Translation heuristics. The Principle of Maximal Logical Revelation. Examples.

Semantic consequence/entailment. Examples. Inference Systems for Propositional Logic. Derivability. Relationship between derivability and entailment. Soundness and completeness.

Required Readings:

  • Propositional Logic slides [pdf]
  • From English to PL slides [pdf] (revised)
  • Derivation systems slides [pdf]
  • Chapter 3 of LRCS book (available on ICON)
  • Chapter 1 of Huth & Ryan (available on ICON)
Recommended Readings:
  • Chapter 2 of LRCS book (as needed)

Exercise in slides

3.1, 3.3-3.5, 3.9 of LRCS
Jan 31
Feb 2
Feb 4

Natural deduction. Derivation rules. Examples of derivations.
Derived rules. Examples of derivations.
In-class exercises on natural deduction proofs.
Proofs of soundness of natural deduction.

Required Readings:

  • Natural deduction slides [pdf]
  • Chapter 1 of Huth & Ryan (available on ICON)
  • Exercises [pdf]

Exercise in slides
Feb 7
Feb 9
Feb 11

Proofs of completeness of natural deduction.

Propositional satisfiability. Truth tables method. Splitting algorithm. Examples.
Improving the performance of the splitting algorithm. Subformula polarity and pure literals. Examples.


Required Readings:
  • Natural deduction slides [pdf]
  • Chapter 1 of Huth & Ryan (available on ICON)
  • Propositional satisfiability slides [pdf] (revised)
  • Chapter 5 of LRCS book (revised)
Exercises in slides
Feb 14
Feb 16
Feb 18

Semantic Tableaux. Solving procedure and examples. Soundness and completeness. In-class exercises. Tableaux as derivation systems. Tableaux derivation rules.

Conjunctive Normal Form and conversion to CNF. Motivation and conversion examples. Conversion to clause form: a space efficient CNF-like transformation.

Required Readings:

  • Semantic Tableaux slides [pdf] (extended)
  • Semantic Tableaux exercise [pdf]
  • CNF and DPLL slides [pdf]
  • Chapters 6 of LRCS book

6.2-6.4,6.6 of LRCS (Chap. 6)
Feb 21

Midterm exam I

Feb 23
Feb 25

Unit propagation. The DPLL procedure, basic version. DPLL improvements: tautology and pure literal elimination, Horn case.

In-class exercises. Encoding cardinality constraints in PL. Reducing puzzle solving to SAT solving. Examples: Sudoko, Loop the Loop.

Required Readings:

  • CNF and DPLL slides [pdf]
  • DPLL exercise [pdf]
  • Chapter 7 of LRCS book

7.3-7.5, 7.7, 7.8, 7.14, 7.15 of LRCS (Chap. 7)
Feb 28
Mar 2
Mar 4

Satisfiability and randomization. k-SAT problem vs SAT-problem. Random clause generation. Probability of generating an unsatisfiable clause set. The sharp phase transition of k-SAT problems. Local search algorithms. Random walk algorithms.

Introduction to quantified Boolean formulas. Game-theoretic view. Syntax and semantics. Free and bound variables.

Required Readings:

  • Satisfiability and Randomization slides [pdf]
  • Chapter 11 of LRCS book
  • Quantified Boolean Formulas slides [pdf]
  • Chapter 12 of LRCS book except for Section 12.4

11.8, 11.10 of LRCS (Chap. 11)
Mar 7
Mar 9
Mar 11

More on QBFs. Rectification. Prenex form. The splitting algorithm for satisfiability checking. CNF for QBEs. DPLL for QBF. DPLL improvements (pure literal rule, universal literal deletion). In-class exercise.

Required Readings:

  • Quantified Boolean Formulas slides [pdf] (revised)
  • Chapter 12 of LRCS book except for Section 12.4

Mar 14
Mar 16
Mar 18

Spring break

Mar 21
Mar 23
Mar 25

Logic and modeling. State-changing systems. Propositional logic of finite domains (PLFD). PLFD and propositional logic. A tableau system for PLFD. Example tableau proof.

State-changing systems. Labelled Transition Systems. Representing states symbolically. Examples. Modeling a vending machine.

Required Readings:

  • PLFD slides [pdf] (revised)
  • Transition systems slides [pdf] (revised)
  • Chapter 13 and 14 of LRCS book

Complete proofs in Examples 2,3 of PLFD notes

13.2, 13.3, 13.7-9, 13.12, 13.14, 14.1, 14.2, 14.4-12 of LRCS
Mar 28
Mar 30

Introduction to Linear Temporal Logic. Computation trees. Expressing temporal properties of transition systems with LTL formulas. Examples.

Required Readings:

  • LTL slides [pdf] (revised)
  • Chapter 15 of LRCS book

15.3-5, 15.8-9 of LRCS
Apr 1

Midterm exam II

Apr 4
Apr 6
Apr 8

More on Linear Temporal Logic. Expressing temporal properties of paths with LTL formulas. Examples. Formula equivalence in LTL. Noteworthy equivalences and non-equivalences.

Modeling systems as transition systems and expressing their properties with LTL formulas. Motivation and examples. In-class modeling exercise.

Required Readings:

  • LTL slides [pdf] (revised)
  • Chapter 15 of LRCS book

Apr 11
Apr 13
Apr 15

The model checking problem. Safety properties and reachability. Symbolic reachability checking. Forward and backward reachability. Examples. Symbolic invariant checking. Inductive strengthening and k-induction. Examples.

Required Readings:

  • Model Checking slides [pdf] (expanded and revised)

Apr 18
Apr 20
Apr 22

More on k-induction. Examples.

Introduction to First-order Logic. Motivation. Syntax and semantics. Quantifiers and qualified quantifiers. Properties of quantifier. From FOL to English. Examples.

Required Readings:

  • Model Checking slides [pdf]
  • First-order Logic slides [pdf] (revised)
  • Sections 2.1,2.2,2.4 of Huth & Ryan (Available on ICON)

Recommended Readings:

Apr 25
Apr 27
Apr 29

From English to Formula. In-class exercises.

The natural deduction calculus for FOL. Rules and example proofs. Soundness and completeness. Undecidability of validity in FOL.

Examples of system modeling and checking in Alloy

Required Readings:

Recommended Readings:

May 2
May 4
May 6

Introduction to Satisfiability Modulo Theories (SMT). Motivation and general idea.

Eager and lazy SMT approaches. Modeling SAT and SMT solvers abstractly as transition systems. DPLL and CDCL transition systems. Transition rules and executions. Examples. Soundness, completeness and termination results.

From propositional CDCL to CDCL modulo theories. Transition rules and executions. Examples. Soundness, completeness and termination results.

Required Readings:

  • SMT slides [pdf] (revised and expanded)

May 9  

Final exam

 

Copyright: Cesare Tinelli, The University of Iowa, 2022