Humanities & academic writing · Mathematics & statistics
forall x: An Introduction to Formal Logic
P. D. Magnus
P. D. Magnus / Fecundity · Version 1.4 [171229], 29 December 2017 · English · Published 2017
An introduction to formal logic, including arguments, sentential logic, truth tables, quantified logic, models, proofs and worked exercise solutions.
- Learning stage
- College introduction
- Prerequisites
- No prior formal logic; comfort with English arguments and symbolic notation.
- PDF pages
- 154 in this file
- Editorial review
- 2026-10-29
Contents
Choose the section you need. Listening availability is shown for each section.
What is logic?
What is logic?
Arguments
Sentences
Two ways that arguments can go wrong
Deductive validity
Other logical notions
Formal languages
Practice Exercises
Sentential logic
Sentential logic
Sentence letters
Connectives
Other symbolization
Sentences of SL
Practice Exercises
Truth tables
Truth tables
Truth-functional connectives
Complete truth tables
Using truth tables
Partial truth tables
Practice Exercises
Quantified logic
Quantified logic
From sentences to predicates
Building blocks of QL
Quantifiers
Translating to QL
Sentences of QL
Identity
Practice Exercises
Formal semantics
Formal semantics
Semantics for SL
Interpretations and models in QL
Semantics for identity
Working with models
Truth in QL
Practice Exercises
Proofs
Proofs
Basic rules for SL
Derived rules
Rules of replacement
Rules for quantifiers
Rules for identity
Proof strategy
Proof-theoretic concepts
Proofs and models
Soundness and completeness
Practice Exercises
Other symbolic notation
Solutions to selected exercises
C Quick Reference
Sources and permissions
The author and publisher remain the source of this textbook. Permission information applies to the specific files in this edition.
Author, publisher, and discovery sources
Authors: P. D. Magnus
Publisher: P. D. Magnus / Fecundity
- Discovered through Open Textbook Library: Source record · Checked 2026-10-29
- Discovered through Open Textbook Library: Source record · Checked 2026-10-25
CC BY 4.0
forall x: An Introduction to Formal Logic by P. D. Magnus,© 2005–2017,version 1.4 [171229]. CC BY 4.0. Original PDF unchanged; Peter Selinger typesetting attribution and other credits retained. No endorsement implied.
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Checked 2026-10-29