Can anybody help me construct a truth table????
I can... but I am limited by the capacity of drawing truth tables here...
we could do one row at a time if that would be easier because i'm not sure how to draw one on here.
I'll give you the basic framework. First, you know your logical operators right? The "not", "and", "or", "implies" etc?
yes
Okay... first thing you gotta do is identify the main operator. Now... let's start with the easiest. \[\large \left[\begin{matrix}\neg & P \\ ? & ? \\ ? &?\end{matrix}\right]\] The main operator here is the negation (NOT) operator, right?
yes
Right. First, pick one of your variables. You only have one, so let's pick P. Under it, write down all possible "truth-values" of P. Truth values just mean either a true or false, 1 or 0, you be the judge. I'll just use T and F. Just tell me if you'd be more comfortable using 1 and 0.
T and F are fine.
\[\large \left[\begin{matrix}\neg & P \\ ? & \color{green}T \\ ? & \color{red}F\end{matrix}\right]\]
Right? Because P can only be either true or false. Catch me so far?
yeah!
Now... what does the "not" operator do to "true" values? What about to "false" values?
makes the true values false, and the false values true?
do you have any expression for which you have to draw a truth table?
Correct. So, write down the effect of the operator... accordingly. \[\large \left[\begin{matrix}\neg & P \\ \color{red}F & \color{green}T \\ \color{green}T & \color{red}F\end{matrix}\right]\] \[\large \left[\begin{matrix}\neg & P \\ \color{red}F &T \\ \color{green}T & F\end{matrix}\right]\] The column underneath the main operator, that is the result of your truth table.
oh okay!
Now, let's do another one... which one do you want, AND, OR, or IMPLIES, or what? :)
so if i give you an example can you help me with it?
Sure. But it might take a while.
that's fine
Hit me~
You're scaring me... this seems lengthy o.O
okay, so i can't get the graph to work but in my solution is pvq...
Just draw it. Or type it out to the best of your abilities :D
the first row is T,T,T,?,? second row is T,T,F,?,? third row is T,F,T,?,?
i have more rows after this
What was given? I mean, the question, what was it?
Was it just p v q ?
all those rows are possible values, but you have to give main question..
probably its not just p v q since 3 columns have T/F values :D
The way I'd work out p v q would involve 3 columns though. Go figure :/
But there are two ?'s on each row, implying five columns... the question, @lexiporter12 ?
here is what im looking at..
i think he has 3 variables
can you see it okay?
okay... it's just p v q after all... Let's put that down... \[\large \left[\begin{matrix}p & \lor & q\\ ? & ? & ? \\ ? & ? & ? \\ ? & ? & ? \\ ? & ? & ?\end{matrix}\right]\]
what is compound statement? and why do you have r?
(pvq)vr a compound statement is what is in the parenthesis
tsk...\[\large \left[\begin{matrix}(p & \lor & q) & \lor & r \\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\end{matrix}\right]\]
Ready to proceed, @lexiporter12 ?
yes
Now, the main operator of your compound statement is this \[\large \left[\begin{matrix}(p & \boxed\lor & q) & \lor & r \\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\end{matrix}\right]\]
right!
Scratch that, I think you misunderstood your own question @lexiporter12 The main operator of p v q is this...\[\large \left[\begin{matrix}(p & \boxed\lor & q) & \lor & r \\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\end{matrix}\right]\] While the main operator of the compound statement is this\[\large \left[\begin{matrix}(p & \lor & q) & \boxed\lor & r \\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\\ ? & ? & ? & ? & ?\end{matrix}\right]\]
ohh okay
so pick a variable... you can pick any variable you want, as long as it's p
well my chart already tells me what the first 3 columns are, so i just need to find the last two
So under the variable p, divide the column into two halves, the first half being TRUE, the second half being FALSE \[\large \left[\begin{matrix}(p & \lor & q) & \lor & r \\ \color{green}T & ? & ? & ? & ?\\ \color{green}T & ? & ? & ? & ?\\ \color{green}T & ? & ? & ? & ?\\ \color{green}T & ? & ? & ? & ?\\ \color{red}F & ? & ? & ? & ?\\ \color{red}F & ? & ? & ? & ?\\ \color{red}F & ? & ? & ? & ?\\ \color{red}F & ? & ? & ? & ?\end{matrix}\right]\]
okay got that
No... you will learn to do this from scratch, @lexiporter12 for your own good :D
haha okay
the 2nd column would be TTFFTTFF
second colum or the column under q.
under q
\[\large \left[\begin{matrix}(p & \lor & q) & \lor & r \\ \color{green}T & ? & \color{green}T & ? & ?\\ \color{green}T & ? & \color{green}T & ? & ?\\ \color{green}T & ? & \color{red}F & ? & ?\\ \color{green}T & ? & \color{red}F & ? & ?\\ \color{red}F & ? & \color{green}T & ? & ?\\ \color{red}F & ? & \color{green}T & ? & ?\\ \color{red}F & ? & \color{red}F & ? & ?\\ \color{red}F & ? & \color{red}F & ? & ?\end{matrix}\right]\]
You can also put the values for r... what would they look like?
TFTFTFTF for r
You see the pattern, right? Alternating T's and F's, but faster alternations every time.\[\large \left[\begin{matrix}(p & \lor & q) & \lor & r \\ \color{green}T & ? & \color{green}T & ? & \color{green}T\\ \color{green}T & ? & \color{green}T & ? & \color{red}F\\ \color{green}T & ? & \color{red}F & ? & \color{green}T\\ \color{green}T & ? & \color{red}F & ? & \color{red}F\\ \color{red}F & ? & \color{green}T & ? & \color{green}T\\ \color{red}F & ? & \color{green}T & ? & \color{red}F\\ \color{red}F & ? & \color{red}F & ? & \color{green}T\\ \color{red}F & ? & \color{red}F & ? & \color{red}F\end{matrix}\right]\]
right
So... what does the v (OR) operator do to two truth values?
make them F
No. The v (OR) operator would be true if AT LEAST ONE of the two values it works with are true. That's why I needed to draw another truth table... \[\large \left[\begin{matrix}P & \boxed\lor &Q\\ \color{blue}T & \boxed{\color{green}T} & \color{blue}T \\ \color{blue}T & \boxed{\color{green}T} & \color{orange}F\\ \color{orange}F & \boxed{\color{green}T} & \color{blue}T\\ \color{orange}F & \boxed{\color{red}F} & \color{orange}F\end{matrix}\right]\]
So... can you finish up the second column?
Remember, under the v (OR) operator, you would put a T if there is a T on the left OR a T on the right.
FFTTT
There are 8 of them...
TTTFFFTT
NO. I told you, if there is at least ONE true value between the two variables (in this case p and q) it would make the value of the v (OR) operator true. For example, in the first row, you have both p and q as T. Therefore, the value of the v (OR) operator on that row is T.
TTTTTTFF
That's much better. And those are the truth values of your statement p v q.
okay so what about the compound statements
\[\large \left[\begin{matrix}(p & \lor & q) & \lor & r \\ \color{green}T & \color{green}T & \color{green}T & ? & \color{green}T\\ \color{green}T & \color{green}T& \color{green}T & ? & \color{red}F\\ \color{green}T & \color{green}T & \color{red}F & ? & \color{green}T\\ \color{green}T & \color{green}T & \color{red}F & ? & \color{red}F\\ \color{red}F & \color{green}T & \color{green}T & ? & \color{green}T\\ \color{red}F & \color{green}T & \color{green}T & ? & \color{red}F\\ \color{red}F & \color{red}F & \color{red}F & ? & \color{green}T\\ \color{red}F & \color{red}F & \color{red}F & ? & \color{red}F\end{matrix}\right]\]
It's the same logic, as with the v (OR) operator, but this time, you compare the truth values of the r-variable to the truth values of the entire pvq statement to the left.
so if at least one of them is true then it makes the compound statement true?
Yes.
TTTTTTTF
And that's your answer. Nicely played.
THANK YUOU
No problem.
I have to go to school now... until the next, guys... ------------------------------------------------ Terence out
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