First order logic proof question
I need to prove this: ⊢ (∀x.ϕ) →(∃x.ϕ)
Using the following axioms:
The only thing I did was use deduction theorem: (∀x.ϕ) ⊢(∃x.ϕ)
And then changed (∃x.ϕ) into (~∀x.~ϕ), so: (∀x.ϕ) ⊢ (~∀x.~ϕ)
How can I continue with this? I cannot use soundness/completeness theorems.
EDIT: ∀* means it is a finite sequence of universal quantifiers (possible 0)