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I need to convert this statement to CNF (Conjunctive normal form):

$\qquad \left((\forall x.\, P(x)) \implies Q(a)\right)\implies \left((\exists y.\, P(y)) \implies Q(a)\right)$

I got this answer:

$\qquad \begin{align} &\left((\forall x.\, P(x)) \lor (\forall y.\, \neg P(y))\right) \\ \land &\left((\forall x.\, P(x)) \lor Q(a) \right)\\ \land &\left(\neg Q(a) \lor (\forall y.\, \neg P(y))\right) \end{align}$

Is it correct? Is there any useful site that I can use to convert statements to CNF?

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It is not clear whether $\forall x$ resp $\forall y$ binds only $P(\_)$ or the respective implications $P(\_) \implies Q(a)$. Please check whether we got it right. – Raphael Feb 2 at 21:15
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Are you certain you intend to use conjunctive normal form? For first-order logic, clausal normal form seems to make more sense. (Also, "check my homework"-type questions are boring. Do you have any conceptual problems?) – Raphael Feb 2 at 21:18

migrated from stackoverflow.com Feb 2 at 17:05

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