what would be the truth table for ~(p ∨ q) ∧ ~p?
lets see if i can write a truth table here
what the heck is a truth table? lol
the explanation the class lesson gives is pretty shoddy so help very much needed :D
ok lets start step by step
\[\begin{array}{|c|c} P & Q \\ \hline T& T \\ T & F \\ F & T \\ F& F\\ \hline \end{array} \] here is our starting piont, it gives all possible combinations of true and false for the two statemenst p and q
so far so good?
yep i got that far
now we have a ~p there so lets add that \[ \begin{array}{|c|c|c} P & Q & \lnot{}P \\ \hline T & T & F \\ T & f & T\\ F & T & F \\ F & F & T \\ \hline \end{array}\] we get that by changes all the T to F under P and vice versa with me so far?
yep
now we also see a \(P\lor Q\) so lets add that for that one, all is true unless both P and Q are false
\[\begin{array}{|c|c|c|c} P & Q & \lnot{}P & P\lor{}Q \\ \hline T & T & F & T \\ T & F & T & T \\ F & T & F & F \\ F & F & T & T \\ \hline \end{array}\]
wait a second i thought ~P= F F T T
yes are right. i was so excited to format the table that i made a mistake good eye
\[\begin{array}{|c|c|c|c} P & Q & \lnot{}P & P\lor{}Q \\ \hline T & T & F & T \\ T & F & F & T \\ F & T & T & F \\ F & F & T & T \\ \hline \end{array}\]
that's better
next line. we need \(\lnot(P\lor Q)\) so we change all the T to F and vice versa under the line \(P\lor Q\)
don't worry, only one more to go
\[\begin{array}{|c|c|c|c|c} P & Q & \lnot{}P & P\lor{}Q & \lnot{}(P\lor{}Q) \\ \hline T & T & F & T & F \\ T & F & F & T & F \\ F & T & T & F & T \\ F & F & T & T & F \\ \hline \end{array}\]
I thought PvQ was....T T T F
let me know if you have any questions thus far one more and we are done
\[\begin{array}{|c|c|c|c|c} P & Q & \lnot{}P & P\lor{}Q & \lnot{}(P\lor{}Q) \\ \hline T & T & F & T & F \\ T & F & F & T & F \\ F & T & T & T & F \\ F & F & T & F & T \\ \hline \end{array}\]
well you caught me again. i wasn't thinking, so i guess you know more than you think on this subject
and more than me at this late hour. but now we are good to go right? because last line is all we need, namely \(\lnot(p\lor q)\land \lnot p\)
Well i kinda only need help with the last one the ~(p ∨ q) ∧ ~p :)
ok well that is it. we only look at the lines \(\lnot(p\lor q)\) and the line \(\lnot p\) and
and the \(\land\) between them means you only get T if both are T
but its V
\[\begin{array}{|c|c|c|c|c|c} P & Q & \lnot{}P & P\lor{}Q & \lnot{}(P\lor{}Q) & \lnot{}(P\lor{}Q)\land{}\lnot{}P \\ \hline T & T & F & T & F & F \\ T & F & F & T & F & F \\ F & T & T & T & F & F \\ F & F & T & F & T & T \\ \hline \end{array}\]
oh nevermind gotcha
if you ever want to generate a nice truth table via the web, and don't mind the fact that they use zeros and ones instead of t and f and write them backwards (zeros first, ones second) try here http://www.kwi.dk/projects/php/truthtable/?
oh thanks a bunch your a real hombre :D
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