Metamath Proof Explorer


Theorem 19.2g

Description: Theorem 19.2 of Margaris p. 89, generalized to use two setvar variables. Use 19.2 when sufficient. (Contributed by Mel L. O'Cat, 31-Mar-2008)

Ref Expression
Assertion 19.2g ⊢ ∀ x φ → ∃ y φ

Proof

Step Hyp Ref Expression
1 19.8a ⊢ φ → ∃ y φ
2 1 sps ⊢ ∀ x φ → ∃ y φ