SOLUTION: Use natural deduction to derive the conclusion in each problem. Use an ordinary proof (not conditional or indirect proof): 1. K ⊃ L 2. ∼K ∨ F 3. (L • F) ⊃

Algebra ->  Proofs -> SOLUTION: Use natural deduction to derive the conclusion in each problem. Use an ordinary proof (not conditional or indirect proof): 1. K ⊃ L 2. ∼K ∨ F 3. (L • F) ⊃      Log On


   

Question 1142475: Use natural deduction to derive the conclusion in each problem.

Use an ordinary proof (not conditional or indirect proof):

1. K ⊃ L
2. ∼K ∨ F
3. (L • F) ⊃ A
4. ∼A / ∼K
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
 1.	K ⊃ L	 
 2.	∼K ∨ F	 
 3.	(L • F) ⊃ A	 
 4.	∼A	      / ∼K

 5.     ~A ⊃ ~(L • F)          3, transposition 
 6.     ~(L • F)               5,4, modus ponens
 7.     K ⊃ F                  2, material implication
 9.     K ⊃ (L • F)            1,7, composition 
10.     ~K                     9,6, modus tollens 

Edwin