Digital library
Textbooks, references and open learning resources.

External
Mathematics for Computer Science
Eric Lehman, F. Thomson Leighton, & Alberty R. Meyer · Google and Massachusetts Institute of Technology
In the contents: 01: Proofs · 01: Intro to Proofs · 1.06: Proving an If and Only If

External
Foundations of Computation
Carol Critchlow & David J. Eck · Hobart and William Smith Colleges
In the contents: 01: Logic and Proof · 1.01: Propositional Logic · 1.03: Application - Logic Circuits

External
Delftse Foundations of Computation
Stefan Hugtenburg & Neil Yorke-Smith · Delft University of Technology
In the contents: 01: Logic · 1.01: Propositional Logic · 1.1.02: Logical operators

External
Discrete Mathematics for Computer Science
Jin He · Fresno City College
In the contents: 01: Introduction to Propositional Logic · 1.04: Proving an If and Only If · 1.05: Proof by Cases

External
Discrete Mathematics for Computer Science
Mark A. Fitch · University of Alaska Anchorage
In the contents: 02: Logic · 2.01: Formal Logic · 2.03: Predicate Logic