1.  AvB     Premise   

2. B—>(AvD) Premise

3. ~D       Premise

4. :: B     Assumption, begin conditional proof (CP) - Case 1

5. :: AvD   4,2  Modus Ponens (MP)

6. :: A     3,5  Disjunctive Syllogism (DS)

7.  :: ~B   Assumption. Case 2

8. ::  A    7,1    DS

9. A        6,8   Proof By Cases (PBC), end of CP,  (A is true under no assumptions)



 

RELATED QUESTIONS

1. (A v B) > ~C
2. C v D
3. A
Conclusion: D  (answered by jim_thompson5910)

1. A -> (B -> C)
2. A -> B
3. ~ C ->(A V D)  / C V... (answered by Edwin McCravy)

I need help finishing this proof.
A v (~B v ~C), A -> (D -> E), ~(~B v ~D) :. C -> (D ->  (answered by jim_thompson5910)

1.	A v (B v C)
2.	C ⊃  (D • E)
3.	~D             / A v B 
 (answered by mccravyedwin)

1. ~ A V (B & E)
2. ~ A -> ~ C
3. C V (B & D)   /... (answered by Edwin McCravy)

1. (A v B) ⊃ (C v D)	
2. C ⊃ E			
3. A • E			/∴ E v... (answered by Edwin McCravy)

1) (A&B) > ~(S v T)
2) ~E
3) (S v T) v ~(~E & ~F)
4) (~E v F) > (A&B)

Conclusion: E  (answered by solver91311)

1. A -> ~(B v C)
2. ~D -> (~A -> ~E)
3. ~(~E v F)
4. ~F -> (A -> B)	/D 
I don't... (answered by Edwin McCravy)

This one is ridiculous, please help me with this proof.

Premises:

1. (~B v A) -> (C  (answered by jim_thompson5910)