predicate

Existential Elimination (EE)

11/3/07

Existential Elimination

10 Software

Reading

Bergmann[2004] The Logic Book Section 10.1.

The Tutorial

Existential Elimination (often called 'Existential Instantiation') permits you to remove an existential quantifier from a formula which has an existential quantifier as its main connective. It is one of those rules which involves the adoption and dropping of an extra assumption (like ∼I,⊃I,∨E, and ≡I).

The circumstance that Existential Instantiation gets invoked looks like this.

Existential Introduction (EI)

11/3/07

Existential Introduction

6/19/07 10Software

Reading

Bergmann[2004] The Logic Book Section 10.1.

The Tutorial

There is a rule for adding a Existential Quantifier, Existential Introduction (also commonly known as 'Existential Generalization'). This permits the step illustrated by the following proof fragments.

2/3/08 10 Software

Quiz 2 Applet

Your browser is not displaying the Deriver applet. Try downloading Deriver itself by clicking on the link elsewhere on the page.

11/4/08 10Software

Skills to be acquired in this tutorial:

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

Reading

M.Bergmann, J.Moor, J.Nelson, [2004] The Logic Book Chapter 9

Tutorial:

Introduction

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

10/24/07 10Software

Skill to be acquired:

To understand the concepts of scope, free, bound. To meet substitution and the rule for removing a Universal Quantifier.

Reading

Bergmann[2004] The Logic Book Section 10.1.

Quiz 7.

6/19/09 10Software

Quiz 7 Applet

The later parts of this can be quite difficult, so it is configured in such a way that the bulk of the work and marks are on intermediate level material. [There is a small quantity of the more challenging material to engage the advanced students.]

12/25/06

Introduction to Free Variables

This video illustrates use of the downloadable application (and the symbol ∧ for 'and' and (∀x) for the universal quantifier, some systems use (x) for this). But, what the film depicts and explains is equally good if you happen to be using the web pages applets (or different symbols for 'and' and the universal quantifier).