gentzen

12/23/20

The logic we are mainly occupied with here is first-order logic (sometimes called first order predicate calculus (with functional terms and identity)). A case can be made that it is the main, or the one true, logic. Sowa writes:

8/14/26

Tutorial 3 Identity: Uniqueness, Definite Descriptions, Iota

Skills to be acquired in this tutorial:

To learn about the Uniqueness quantifier (a part of identity), and to be introduced to definite descriptions.

Why this is useful:

Uniqueness is central in mathematics, and definite descriptions is a core area in philosophical logic.

8/11/26

Skills to be acquired in this tutorial:

To learn about functional terms and two new Rules of Inference II (Identity Introduction) and IE (Identity Elimination).

Why this is useful:

Reasoning with identity is vital for mathematics, philosophy, and many other areas.

8/11/26

Skills to be acquired in this tutorial:

To start to learn about identities, the semantics of identities, and typical expressions in English that might use identities.

Why this is useful:

Reasoning with identity is vital for mathematics, philosophy, and many other areas.

12/19/20

Welcome!

The tutorials presented here look at some topics in logic to the level of intermediate to advanced Predicate Calculus. They build on the Tutorials of Easy Deriver which provided the introductory material to Propositional and Predicate Calculus.

The program, widgets, or Notes, should be accompanied by a suitable textbook, such as:

These Gentzen Notes were brought in to the Content Management System from earlier Notes which were outside. The earlier Notes can be found at http://softoption.us/test/easyDeriver/tutorials/index.html

4/24/06

Tutorial 25 Exercises h

4/24/06

Tutorial 25 Exercises g

4/24/06

Tutorial 25 Exercises e