Thread: How to write propositions into symbolic forms

Well I was wondering if there is a method which some one follows to solve questions like these..

Here is an example

The square of every real number is a non-negative number

(for all x)(x element of Z) --> (x^2>0)

is this how you write it ? btw I used A upside down for (for all x)

if you can kindly post any websites that teaches how to master this

Thanks

http://en.wikipedia.org/wiki/Set_(mathematics)

this is what I founded in 1 min., just google it... and you will find what you want.

Hello Khonics89

Originally Posted by Khonics89

Well I was wondering if there is a method which some one follows to solve questions like these..

Here is an example

The square of every real number is a non-negative number

(for all x)(x element of Z) --> (x^2>0)

is this how you write it ? btw I used A upside down for (for all x)

if you can kindly post any websites that teaches how to master this

Thanks

You have nearly got it right. We usually use to denote the real numbers, and 'non-negative' means 'greater than or equal to zero'. So the correct answer would be:



If you want some on-line material that introduces Logic to a beginner, you'll find some notes (with lots of worked examples and exercises) that I wrote for Wikibooks starting just here. And in particular, the use of quantifiers is covered just here.

Grandad