Metamath Proof Explorer


Theorem exellim

Description: Closed form of exellimddv . See also exlimim for a more general theorem. (Contributed by ML, 17-Jul-2020)

Ref Expression
Assertion exellim ⊢ ∃ x x ∈ A ∧ ∀ x x ∈ A → φ → φ

Proof

Step Hyp Ref Expression
1 nfa1 ⊢ Ⅎ x ∀ x x ∈ A → φ
2 nfv ⊢ Ⅎ x φ
3 sp ⊢ ∀ x x ∈ A → φ → x ∈ A → φ
4 1 2 3 exlimd ⊢ ∀ x x ∈ A → φ → ∃ x x ∈ A → φ
5 4 impcom ⊢ ∃ x x ∈ A ∧ ∀ x x ∈ A → φ → φ