People of ef, I need your help with BASIC LOGIC!!!

[MaGilicuti]

I am doing my online tests now, 2 tests to go. I am completely lost. Please help me god

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Question 1 (10 points)
Please derive ( A & B) --> D from the premise B --> D.
Prove A & B) --> D
1) B --> D P

Question 2 (10 points)
Please derive A --> B from the premises A --> ( ~~B v C), ~C
Prove: A --> B
1) A --> ( ~~B v C) P
2) ~C P


Question 3 (10 points)
Please derive ~A from A --> B, B --> C, ~C
(Hint: Use ~I)
Prove: ~ A
1) A --> B P
2) B --> C P
3) ~C P

Question 4 (10 points)
Please derive: A --> ~C from A <--> B, B <--> ~C.
Prove: A --> ~C
1) A <--> B P
2) B <--> ~C P


Question 5 (10 points)
Prove: A --> D from A --> B, (B & C) --> D, C.
Prove: A --> D
1) A --> B P
2) (B & C) --> D P
3) C P

Question 6 (10 points)
Please prove D from A --> B, B --> A, ( A <--> B) --> ~C, C v D.
Prove: D
1) A --> B P
2) B --> A P
3) ( A <--> B) --> ~C P
4) C v D P

Question 7 (10 points)
Prove A --> D from ( A v B) --> ~C, C v D.
Prove: A --> D
1) ( A v B) --> ~C P
2) C v D P

Question 8 (10 points)
Prove C & D from A <--> ~B, ~B --> ~~C, A, D.
Prove: C & D
1) A <--> ~B P
2) ~B --> ~~C P
3) A P
4) D P

Question 9 (10 points)
Prove ~A from A --> ~B, B v ~~C, C --> ~A.
Hint: Use ~I
Prove: ~A
1) A --> ~B P
2) B v ~~C P
3) C --> ~A P

Question 10 (10 points)
Prove: ~(A & B) from the premise ~A v ~B
Use ~I
Prove: ~( ~A & ~B)
1) A v B P

 

[MommaKin]

I'm calling God right now.....so far he isn't answering.....
I think you SOL, unless someone on here can help..
Waiting for God to help will be like waiting for hell to freeze over

 

[MaGilicuti]

I'm calling God right now.....so far he isn't answering.....
I think you SOL, unless someone on here can help..
Waiting for God to help will be like waiting for hell to freeze over

this doesn't look good

 

[68GT350]

your an idiot.

 

[Stryc-9]

Are you sure you wrote the questions out correctly?? There seem to be missing premisses.....

Question one must have other premisses - you cannot derive anything from a simple conditional!!


I think question three might go like this:

p1. A ---> B
p2. B ---> C
p3. ~C
p4. ~B (citing Modus Tollens, p2, p3)
p5. ~A (citing Modus Tollens, p1, p4)

Wait a sec - are you even online anymore?!?!......ah screw this....

 

[Stryc-9]

yeah so I just realized I'm an hour late to respond....sorry Magilicuti...

Anyway, I only know eight basic inference rules for performing deductions in symbolic logic (Modus Ponens, Modus Tollens, Disjunctive Syllogism, Additition, Adjunction, Simplification, Hypothetical Syllogism, and Constructive Dilemma....)

And I don't remember how to handle biconditionals.....so I probably wouldn't have been much help....I suck....

 

[Lao Tzu]

i think i speak for the board when i say WHAT THE FUCK?

prove A --> B? what does --> mean? =, <, >, etc?

 

[Stryc-9]

i think i speak for the board when i say WHAT THE FUCK?

prove A --> B? what does --> mean? =, <, >, etc?

"A --> B" is just a way of symbolizing a simple conditional statement form....it should be read as:

"If A then B"

It's symbolic logic - it's whack....

 

[chesty]

--> means logically implies

so A&B-->D logically implies that A&B result in D

Therefore, if B-->D

Then A must -->D

Since A and B --> D

or some shit like that. I have not done logic in years.

 

[mattcanning99]

mac, have you written the test yet?

if you ever need help with math, email me in advance, it's my major, and i know logic, calc, etc pretty well

 

[Lao Tzu]

mac, have you written the test yet?

if you ever need help with math, email me in advance, it's my major, and i know logic, calc, etc pretty well

i love that avatar. i may have to get one like that. goofus & galiant i think. highlights.