Metamath Proof Explorer


Theorem r19.29a

Description: A commonly used pattern in the spirit of r19.29 . (Contributed by Thierry Arnoux, 22-Nov-2017) Reduce axiom usage. (Revised by Wolf Lammen, 17-Jun-2023)

Ref Expression
Hypotheses rexlimdva2.1 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝜓 ) → 𝜒 )
r19.29a.1 ( 𝜑 → ∃ 𝑥𝐴 𝜓 )
Assertion r19.29a ( 𝜑𝜒 )

Proof

Step Hyp Ref Expression
1 rexlimdva2.1 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝜓 ) → 𝜒 )
2 r19.29a.1 ( 𝜑 → ∃ 𝑥𝐴 𝜓 )
3 1 rexlimdva2 ( 𝜑 → ( ∃ 𝑥𝐴 𝜓𝜒 ) )
4 2 3 mpd ( 𝜑𝜒 )