Logic Tutorial
- http://logictutorial.com/
- An interactive tool teaching basic formal logic, rendering truth tables as clickable Johnston diagrams. With notes on the Buddhist Nagarjuna and modern symbolic logic.
Logical Laws
- http://sakharov.net/logic.html
- This page includes a collection of logical laws of the first-order logic. This collection is based on the Kleene's collection from his books 'Introduction to Metamathematics' and 'Mathematical Logic' and includes a few additions.