Any help is appreciated.. here is what im dealing with
I am writing everything as it appears on the worksheet
1.~XvY
2.~F
3. D (horseshoe) X
4.~Y&F
/~D&F
1.K (horseshoe) C
2. K&G
3. C (horseshoe) ~F
4. ~D
5. ~F (horseshoe) D
/~Kv~R
Logical Proofs, Need help desperately!
- Arising_uk
- Posts: 12314
- Joined: Wed Oct 17, 2007 2:31 am
Re: Logical Proofs, Need help desperately!
By (horseshoe) do you mean set union U?
If so I'm surprised to find this in predicate logic. Could you give a bit of context to where these proofs are coming from?
If so I'm surprised to find this in predicate logic. Could you give a bit of context to where these proofs are coming from?
Re: Logical Proofs, Need help desperately!
When people say "horseshoe" they usually mean horseshoe but you can't take anything for granted round here.Arising_uk wrote:By (horseshoe) do you mean set union U?
- Arising_uk
- Posts: 12314
- Joined: Wed Oct 17, 2007 2:31 am
Re: Logical Proofs, Need help desperately!
I was wondering if it was just the Logic teacher showing that any symbol can be used to express some kind of logical operator or relation.
-
- Posts: 4369
- Joined: Wed Feb 10, 2010 2:04 pm
Re: Logical Proofs, Need help desperately!
Mr. Ed used horseshoe logic...
-Imp
-Imp
- Necromancer
- Posts: 405
- Joined: Thu Jul 30, 2015 12:30 am
- Location: Metropolitan-Oslo, Norway, Europe
- Contact:
Re: Logical Proofs, Need help desperately!
This is sentential logic.
Some suggestion:
1.~XvY
2.~F
3. D (horseshoe) X
4.~Y&F
-----------------------
5. ~Y conj. elim. 4.
6. F conj. elim. 4.
7. ~XvY reiteration 1.
8. | ~X
---------
9. | ~X
10. | Y
------------
11. | ~X
12. ~X disj. elim. 7.-11.
13. ~D modus tollens 3., 12.
------------------------
/~D&F conj introd. 6., 13.
Here is your "horseshoe": ⊃ from http://lukasfolsneslea.tripod.com/HTML-LN-charsym1.html.
The logic book your looking for is The Logic Book 5th ed. or so by M. Bergmann, J. Moor and J. Nelson.
Some suggestion:
1.~XvY
2.~F
3. D (horseshoe) X
4.~Y&F
-----------------------
5. ~Y conj. elim. 4.
6. F conj. elim. 4.
7. ~XvY reiteration 1.
8. | ~X
---------
9. | ~X
10. | Y
------------
11. | ~X
12. ~X disj. elim. 7.-11.
13. ~D modus tollens 3., 12.
------------------------
/~D&F conj introd. 6., 13.
Here is your "horseshoe": ⊃ from http://lukasfolsneslea.tripod.com/HTML-LN-charsym1.html.
The logic book your looking for is The Logic Book 5th ed. or so by M. Bergmann, J. Moor and J. Nelson.
- Arising_uk
- Posts: 12314
- Joined: Wed Oct 17, 2007 2:31 am
Re: Logical Proofs, Need help desperately!
Oh! Now I get it, the material conditional, doh!
He could have said 'right horseshoe' or 'left horseshoe' for a better clue.
He could have said 'right horseshoe' or 'left horseshoe' for a better clue.