Proving the following proposition

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I am asked to prove the following proposition but, due to omissions or just plain ignorance I've been unable to arrive at the correct answer. Your input will be greatly appreciated. enter image description here

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Intuitively we can reason that no object $a$ can satisfy $p$ because if it did we'd also have that something is $q$ (by first premiss), which is ruled out (by the second premiss). So, turning that idea into a natural deduction proof:

Start a subproof with $p(a)$.

Then it follows $\exists x p(x)$, and hence by the first premiss $\exists y q(y)$.

But $\exists y q(y)$ and the second premiss lead to contradiction.

Since $p(a)$ leads to contradiction we can apply reductio, drop the supposition, and conclude $\neg p(a)$.

Universal quantifier introduction gives the target result.

How that goes in detail will depend on the system you are working with.