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Question: Construct a proof!.!.!.!. HELP!!?
1!. (~K & N) > [(~P > K) & (~R > G)]
2!. K > N
3!. ~N & B
4!. ~P v ~R /G


it should take six lines
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Best Answer - Chosen by Asker:
Im pretty sure something is wrong with your premises!.

The only way to arrive at G is is through Disjunctive Syllogism in K∨G with a ~K!.

The only way to arrive at K∨G is through Constructive Dilemma in
(~P ? K) ? (~R ? G) and ~P∨~R!. You already have the latter of the two!.

The former of the two can only be proven via Modus Ponens in a true antecedent!. But the antecedent is obviously false, since it is a conjunctive statement and N is false!. We know N is false because ~N is a conjunct in your third premise

See that!? G is hidden in only one spot!.!.!. in the consequence of a conditional!. Since the premise is false, there is no way to assert the truth value of the consequenceWww@QuestionHome@Com

Cogito ran into the same problem I faced!. I notice that B is a premise that is simply stated but plays no role in the rest of the argument!. Did you perhaps forget to include a premise that involves B!?Www@QuestionHome@Com

see other answer!. argument is not valid!.Www@QuestionHome@Com