Metamath Proof Explorer


Theorem spimevw

Description: Existential introduction, using implicit substitution. This is to spimew what spimvw is to spimw . Version of spimev and spimefv with an additional disjoint variable condition, using only Tarski's FOL axiom schemes. (Contributed by NM, 10-Jan-1993) (Revised by BJ, 17-Mar-2020)

Ref Expression
Hypothesis spimevw.1 ( 𝑥 = 𝑦 → ( 𝜑𝜓 ) )
Assertion spimevw ( 𝜑 → ∃ 𝑥 𝜓 )

Proof

Step Hyp Ref Expression
1 spimevw.1 ( 𝑥 = 𝑦 → ( 𝜑𝜓 ) )
2 ax-5 ( 𝜑 → ∀ 𝑥 𝜑 )
3 2 1 spimew ( 𝜑 → ∃ 𝑥 𝜓 )