Question 1029805
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This one involves material implication 
P &#8835; Q is equivalent to ~P v Q


1. A &#8835; U
           / A &#8835; (K &#8835; U)

2. ~A v U           1, Material implication
3. ~A v (U v ~K)    2, Addition  
4. ~A v (~K v U)    3, Commutation
5. A &#8835; (~K v U)     4, Material implication
6. A &#8835; (K &#8835; U)      5, Material implication

Edwin</pre>