# identity

Tree Tutorial 5: Identity Rules admin Tue, 05/29/2012 - 21:38
Topic
Logical System

### Skills to be acquired in this tutorial:

To become familiar with the new rules for predicate logic trees with identity.

### Tutorial:

It is possible to use trees with formulas containing identity. Really there are two different ways to implement it: either there are two new rules, or there is one new rule and a new way of closing a branch from a single formula. Both will be described.

## Uniqueness

Topic
Logical System

### 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.

Help with the Uniqueness Rules martin Wed, 01/14/2009 - 10:31
Topic
Logical System

1/17/20

Help with the Identity Rules martin Wed, 01/14/2009 - 09:51
Topic
Logical System

1/17/20

[This is a film-- press the 'play' symbol.]

Help with Drawings for Identity martin Wed, 01/14/2009 - 09:36
Topic
Logical System

1/9/09

Your browser does not support the video tag. -->

[What is shown below is a Video, with sound. Your computer should be able to run this. If you have external speakers, or similar, you may need to turn them on and turn the volume up.]

The video shows an older implementation (but it should convey the principles).

Tutorial 3 Identity: Uniqueness, Definite Descriptions, Iota martin Sat, 01/03/2009 - 20:45
Topic
Logical System

## Tutorial 3 Identity: Uniqueness, Definite Descriptions, Iota

2013

### 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.

## Tutorial 2 Identity: Functional Terms and Rules of Inference

Topic
Logical System

### 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.

## Tutorial 1: Identity, Semantics and Symbolization

Topic
Logical System

### 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.

## Deriver [Functional Terms, Identity, First Order Theories, Set Theory—Gentzen Syntax]

Topic
Logical System
###### 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:

Tree Tutorial 5: Identity Rules martin Sun, 07/27/2008 - 15:14
Topic
Logical System

2013

### Skills to be acquired in this tutorial:

To become familiar with the new rules for predicate logic trees with identity.

Colin Howson, [1997] Logic with trees Chapter 9

### Tutorial:

It is possible to use trees with formulas containing identity. Really there are two different ways to implement it: either there are two new rules, or there is one new rule and a new way of closing a branch from a single formula. Both will be described.