Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**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)*

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,789

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

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

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,891

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?

Here lies the reader who will never open this book. He is forever dead.

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.

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,789

Do you know what a truth table is?

Bob

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

Offline

**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 |

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,789

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

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

Offline

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

Thanks, Bob.

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

Offline