This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer


Theorem ax5ea

Description: If a formula holds for some value of a variable not occurring in it, then it holds for all values of that variable. (Contributed by BJ, 28-Dec-2020)

Ref Expression
Assertion ax5ea ( ∃ 𝑥 𝜑 → ∀ 𝑥 𝜑 )

Proof

Step Hyp Ref Expression
1 ax5e ( ∃ 𝑥 𝜑𝜑 )
2 ax-5 ( 𝜑 → ∀ 𝑥 𝜑 )
3 1 2 syl ( ∃ 𝑥 𝜑 → ∀ 𝑥 𝜑 )