Name ________________________   Logic Homework 9.  Date ______________

Circle the valid arguments, and cross out the invalid ones.

1. ~Py
    Qz ^ Py
    Qz	
2. Rm ^ Sn
    Sn
    Rm	
3. Bk v Cl
    Cl ^ Bk
	
4. Fo
    Gp ^ Fo
	
5. ~To
    To ^ Up
    Up	
6. Lu v Mv
    ~Mv
    Lu	

7. Hq v Ir
    ~Hq
    ~Ir	
8. Js v Kt
    Js
    ~Kt

	

	

Prove the following arguments valid by DERIVATION. 

19.  Ia v Mu			1. Show  							
       No v (Mu v Ia)		
				2. 								
				
				3. 								
				
				4. 								
				
				5. 								

			2. 								

				3. 								
				
				4. 								
				
				5. 								

21. Iu v (Ge ^ He)		1. Show  							
      ~Iu						
      He v Ge			2. 								

				3. 								
				
				4. 								
				
				5.