Help with indirect logic proof please

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    Logic Proof
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The discussion focuses on proving the implication p→q using five axioms: A1: p→~y, A2: ~r→q, A3: p→~z, A4: x→q or z, and A5: r→x or y. Participants suggest that taking the contrapositive of some axioms is not required for the proof. Instead, they recommend utilizing the tautology (r or ~r) and applying or-elimination to demonstrate that assuming p leads to both r → q and ~r → q.

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LCharette
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Using the five axioms below prove: p→q

A1: p→~y
A2: ~r→q
A3: p→~z
A4: x→ q or z
A5: r→x or y

Do I have to take the contrapositive of some of the axioms to begin this proof?
 
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Not necessarily.
You can also solve it using the tautology (r or ~r) and using or-elimination (i.e. assuming p, show that r -> q and ~r -> q).
 

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