i hope that someone could help me with my q's here:

http://www.physicsforums.com/showthread.php?t=97985

i searched in the homework section and there isn't a section for logic an set theory so i ask my questions here (begging for replies):

1)expand the proposition (by the equivalence rules):

[~(pvq)v((~p)^q)]

i got to this: [(~pv~p)^(~pv~q)]^[(qv~p)^(qv~q)]

is it correct?

 

I didn't know about the second question you gave' date=' but as to this question:

 

You give:

[~(pvq)v((~p)^q)']

 

Which I would first do:

[(~p^~q)v(~p^q)]

 

In both cases ~p must be true, and either q or ~q would satisfy, so you have

~p^(qv~q)

 

Now it depends if you accept the law of the excluded middle. If you do, (meaning that you accept that q must be true or not true), then it follows that the expression is equivalent to

~p

 

Hope this helps.

thanks.

can someone help me with the second one?

my question is still remains open, someone?

i appreciate the help if you can hand in some.