Question 970141
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 1.	A &#8835; (Q &#8744; R)	
 2.	(R • Q) &#8835; B	
 3.	A • &#8764;B	
/ R &#8801; &#8764;Q

 4.     A              simplification,3
 5.    ~B              simplification,3
 6.  ~B &#8835; ~(R • Q)     contrapositive,2
 7. ~(R • Q)           modus ponens,6,7
 8.  ~R &#8744; ~Q           deMorgan's,7
 9 .  R &#8835; ~Q           writing a disjunction as a conditional,8 
10.   Q &#8744; R            modus ponens,1,4      
11. ~~Q &#8744; R            double negation,10
12.  ~Q &#8835; R            writing a disjunction as a conditional,11
13. R &#8801; &#8764;Q             definition of equivalence, 9,12 

Edwin</pre>