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

You are not logged in.

• Index
•  » Help Me !
•  » What does the 'p' in the beginning mean? (Logic/Truth table question)

## #1 2012-10-17 04:10:00

genericname
Full Member

Offline

### What does the 'p' in the beginning mean? (Logic/Truth table question)

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 (2012-10-17 04:10:16)

## #2 2012-10-17 04:30:21

bob bundy
Moderator

Online

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

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

## #3 2012-10-17 05:01:42

anonimnystefy
Real Member

Offline

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

#### 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?

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #4 2012-10-17 05:17:36

bob bundy
Moderator

Online

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

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

## #5 2012-10-17 05:27:11

genericname
Full Member

Offline

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

#### 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   |

## #6 2012-10-17 05:41:12

bob bundy
Moderator

Online

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

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

## #7 2012-10-17 06:31:21

genericname
Full Member

Offline

### Re: What does the 'p' in the beginning mean? (Logic/Truth table question)

Thanks, Bob.

Last edited by genericname (2012-10-17 06:31:37)

• Index
•  » Help Me !
•  » What does the 'p' in the beginning mean? (Logic/Truth table question)