Exercises for Chapter 6, part 2
10 points.
Due Weds., April 11, 10pm
Use the Natural-deduction-proof-checker to prove these claims, and submit your answers within a zipped folder. Do your own work.
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1.
∀x(F(x) —> G(x)), F(chuck) |- ∃x(F(x) ^ G(x))
(use ∃i, not ∃e)
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2.
∃x(F(x) —> G(x)), ∀y F(y) |- ∃z G(z)
(Use ∃i and ∃e. )
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3.
∃x F(x) |− ~(∀x ~F(x))
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4.
∀x(F(x) —> ∃y G(x,y)) |- (∃z F(z)) -> (∃z ∃y G(z,y))