How to Prove Predicate Logic Validity with Induction?

[Voehet]

How would I go about proving that the argument below is valid using the induction method?
(∃x)[P(x)!Q(x)]^(∀y)[Q(y)!R(y)]^(∀x)P(x)!(∃x)R(x)

Thank you very much in advance!

 

[MarkFL]

Hello and welcome to MHB, Voehet! :D

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Can you post what you have done so far?

 

[Evgeny.Makarov]

How would I go about proving that the argument below is valid using the induction method?
(∃x)[P(x)!Q(x)]^(∀y)[Q(y)!R(y)]^(∀x)P(x)!(∃x)R(x)

What does ! stand for?