# Laboratory Work 4 — Advanced Propositional Logic and Computational Logic

> Fourth laboratory work of **Computer Discrete Mathematics**. You implement a
> propositional-logic **expression evaluator** — computing the truth value of a
> formula under a given assignment — and an **automated truth-table generator**
> for formulas built from `AND`, `OR`, and `NOT`.

## At a glance

| | |
|---|---|
| **Topic** | Propositional logic: connectives, expression evaluation, truth tables |
| **Prerequisite lectures** | [L04 — Boolean algebra (basics)](../../Lectures/CDM-L04.md), [L06 — Propositional logic](../../Lectures/CDM-L06.md) |
| **Deliverable** | Source code + report (see [5report.md](5report.md)) |
| **Structure** | Two tasks: expression evaluation and truth-table generation (see [4task.md](4task.md)) |

## Contents

| # | Part | File |
|:--:|---|---|
| 1 | Objective | [1purpose.md](1purpose.md) |
| 2 | Methodical guidelines (theory & algorithms) | [2method.md](2method.md) |
| 4 | Task and order of execution | [4task.md](4task.md) |
| 5 | Report contents | [5report.md](5report.md) |
| 6 | Control questions | [6questions.md](6questions.md) |

## Conventions

- **Language** — source code and the report are in **English**.
- **Implement it yourself — no built-in shortcuts.** Do not call a library or
  built-in that performs the core task for you (e.g. no `HashSet`/`set()`/`Set`
  for sets, no library graph/relation type, no `math.gcd`, no `eval`). Build the
  mechanism from basic primitives — arrays/lists, loops, arithmetic, strings.
- **Deliverable** — submit the source code **and** a report structured as in
  [5report.md](5report.md); the code must reproduce the example outputs in
  [4task.md](4task.md).
- **Self-contained theory** — everything needed is in [2method.md](2method.md);
  no external material is required.

## Summary

A **proposition** is a statement that is either true or false, and the
connectives `NOT`, `AND`, and `OR` combine propositions into compound formulas.
Two questions drive this work: *what is the value of a formula under a specific
assignment of truth values to its variables* (evaluation), and *what are its
values under **all** possible assignments* (its truth table). Implementing both
requires parsing an expression with the correct operator precedence and
enumerating the $2^n$ assignments of its $n$ variables — the computational core
that underlies circuits, SAT solving, and the rest of logic in the course.