To do a tableau proof of this statement:(adsbygoogle = window.adsbygoogle || []).push({});

[tex](\forall x) [P(x) \vee Q(x)] \supset [(\exists x)(P(x) \vee (\exists x)(Q(x)] [/tex]

I started out by restating it as follows:

[tex](\forall x) [P(x) \vee Q(x)] \supset [(\exists y)(P(y) \vee (\exists z)(Q(z)] [/tex]

to avoid confusion over what's bound to what (and when).

Is my approach:

valid?

invalid?

recommended?

not?

a good idea?

not?

some other adjective (or expletive)?

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# First order proof

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