Question 1179970
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1.I v (N • F)
2.I ⊃ F        /  F
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Derivation	      Line(s) Used	Rule Used / Justification
3.( I v N) • (I v F)	1	        Dist
4. (I v F) • ( I v N)	3	        Comm
5.(I v F)	        4               Simp
6.~I ⊃F          	5	        Impl
7.~F ⊃ ~~I      	6	        Trans
8.~F ⊃ I	        7	        D.N.
9.~F ⊃F	                2,8	        H.S.
10.~~F v F	        9 	        Impl
11.F v F         	10	        D.N.
12 F	                11	        Taut

[Just want to note that line 9 may confuse some readers because I listed the 2 before the 8 and the form does not match the rule as written.  In that case all one needs to do is use line 8 before line 2 for the form to be correct].


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