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**genericname****Member**- Registered: 2012-05-16
- Posts: 52

http://i.imgur.com/qGLc1.png

Hi,

Does it mean that all the P's for that problem are true? The problem is telling me to use a truth table to tell whether or not the statement is true and the 'p' in front put me off.

*Last edited by genericname (2012-10-16 05:10:16)*

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,376

hi genericname

The notation is a little unclear but compare with

http://www.cs.odu.edu/~toida/nerzic/lev … L/E2L.html

I think

p, p<=>q means p and p<=>q

The truth tables agree with p^q and you can only test the equivalence if you can also consider the cases where p is false.

Hope that's right.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 15,954

bob bundy wrote:

The truth tables agree with p^q and you can only test the equivalence if you can also consider the cases where p is false.

What do you mean by this?

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,376

Do you know what a truth table is?

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**genericname****Member**- Registered: 2012-05-16
- Posts: 52

bob bundy wrote:

hi genericname

The notation is a little unclear but compare with

http://www.cs.odu.edu/~toida/nerzic/lev … L/E2L.html

I think

p, p<=>q means p and p<=>q

The truth tables agree with p^q and you can only test the equivalence if you can also consider the cases where p is false.

Hope that's right.

Bob

So it saying to compare the values of p^q with p<=>q?

p | q | p<=>q | p^q |

0 | 0 | 1 | 0 |

0 | 1 | 0 | 0 |

1 | 0 | 0 | 0 |

1 | 1 | 1 | 1 |

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,376

hi genericname

The truth table below shows what I did. I'm not saying it is correct; to tell the truth that comma has me puzzled too. I'd prefer all compound statements to be made using only propostional calculus notation.

Have a look back at your notes / text book. What is a comma supposed to mean?

If you take a look at that link I gave you, you'll find the author uses two different notations:

notation 1

statement 1

statement 2 underneath

notation 2

statement 1 & statement 2

I assumed that the comma was the equivalent of notation 1.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**genericname****Member**- Registered: 2012-05-16
- Posts: 52

Thanks, Bob.

*Last edited by genericname (2012-10-16 07:31:37)*

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