Metamath Proof Explorer


Theorem 19.37iv

Description: Inference associated with 19.37v . (Contributed by NM, 5-Aug-1993) Remove dependency on ax-6 . (Revised by Rohan Ridenour, 15-Apr-2022)

Ref Expression
Hypothesis 19.37iv.1 ⊢ ∃ x φ → ψ
Assertion 19.37iv ⊢ φ → ∃ x ψ

Proof

Step Hyp Ref Expression
1 19.37iv.1 ⊢ ∃ x φ → ψ
2 19.37imv ⊢ ∃ x φ → ψ → φ → ∃ x ψ
3 1 2 ax-mp ⊢ φ → ∃ x ψ