Inference Method in Logic

I have an assignment from my lecturer and I'm not sure with my answer. Could you share your answer so I can compare and check with my answer... Thanks for helping...

Question: Prove that:

1st Statement : p -> q v r 2nd Statement : ~q v ~r Conclusion : ~p v ~r

is invalid!!!

My last prove is : ~(~p v r) v (~p v q). Is it true?

#Logic #ComputerScience #Proofs #Inference

Easy Math Editor

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Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$