trees

8/12/26

Skills to be acquired in this tutorial:

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

Reading

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.

2/3/08 10 Software The Widget for this has yet to be written.

However, the Tree Quiz can be done in the web application.

You might want to glance at Deriver in a web page Then you can launch Deriver from here Deriver20 [Howson Parser].  

Preferences

You will need the relevant Preferences for this.

9/16/08 10 Software

Reading

Richard Jeffrey, [1967-2006] Formal Logic: its Scope and Limits

8/12/26

Skills to be acquired in this tutorial:

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

Reading

Colin Howson, [1997] Logic with trees Chapter 6

Tutorial:

Introduction

There are further rules for predicate logic trees (which we will come to shortly).

Tree Quiz 1.

8/16/26 10 Software. The Widget for this has yet to be written. 2013

However, the Tree Quiz can be done in the web application.

You might want to glance at Deriver in a web page Then you can launch Deriver from here Deriver20 [Howson Parser].  

Preferences

You will need the relevant Preferences for this.

8/16/26

Reading

Colin Howson, [1997] Logic with trees Chapter 2

Exercises

Howson [1997] has a number of exercises. Many of them you will be able to do in the Widget below.

You can also try material of your own.

Here are a few hints

2013

Skills to be acquired in this tutorial:

To become familiar with the notions of closed and complete trees. To be able to use trees to test for satisfiability and invalidity.

Reading

Colin Howson, [1997] Logic with trees Chapter 2

Tutorial:

Closure and completeness

In Tutorial 1, we met the notions of closed and open branches (a closed branch was one containing a formula and also the negation of that formula, an open branch was a branch that was not closed).

Beginning Trees

2/10/08

A Simple Tree

[This is a Quicktime Movie, click the Play button to view it. The logical symbols you see in use may be different to the ones you are familiar with (sorry about that, but it is not practical to produce different movies for all the minor variations in symbols). Any differences will not affect the principles being explained here.]

2013

Tree Tutorial 2 More Rules

12/12/2020

Skills to be acquired in this tutorial:

To become familiar with the rules for propositional truth trees.

Reading

Colin Howson, [1997] Logic with trees Chapter 2

Tutorial:

Truth Tree Rules

Trees are going to be used to 'picture' the truth conditions or requirements for a formula (then, as the technique is developed, for several formulas at once).