The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Math Topics » geometry.pre-college

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Logic Help
Replies: 1   Last Post: Jul 30, 1998 11:58 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Michael Thwaites

Posts: 22
Registered: 12/6/04
Re: Logic Help
Posted: Jul 30, 1998 11:58 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Russell -

I would prove this by trying all the possible values of P and Q. There are
only Four combinations, T,T, T,F, F,T and F,F for P,Q. Evaluate the left
and right sides of each equation for each of the four cases and see if they
are equal.


>Can anyone help me prove the following three equivalences:
>(P or Q) and not(P and Q) = (P and notQ) or (Q and notP)
>P <---> Q = (P and Q) or (notP and notQ)
>(P ---> R) and (Q ---> R) = (P or Q) ---> R
>If you could email me with the proofs, I would very much appreciate it.
>Thanx in advance.
> -Russell (

Date Subject Author
Read Logic Help
Read Re: Logic Help
Michael Thwaites

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.