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Theorem ralsex 50457
Description: The consequent of an "all some" restricted to a class is witnessed: some member of 𝐴 satisfying 𝜑 also satisfies 𝜓. Restricted counterpart of alsex 50456. (Contributed by David A. Wheeler, 12-Jul-2026.)
Assertion
Ref Expression
ralsex (∀∃𝑥𝐴(𝜑𝜓) → ∃𝑥𝐴 𝜓)

Proof of Theorem ralsex
StepHypRef Expression
1 df-rals 50447 . 2 (∀∃𝑥𝐴(𝜑𝜓) ↔ (∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑))
2 rexim 3112 . . 3 (∀𝑥𝐴 (𝜑𝜓) → (∃𝑥𝐴 𝜑 → ∃𝑥𝐴 𝜓))
32imp 411 . 2 ((∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑) → ∃𝑥𝐴 𝜓)
41, 3sylbi 220 1 (∀∃𝑥𝐴(𝜑𝜓) → ∃𝑥𝐴 𝜓)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 400  wral 3085  wrex 3095  ∀∃wrals 50445
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836
This theorem depends on definitions:  df-bi 210  df-an 401  df-ex 1807  df-ral 3086  df-rex 3096  df-rals 50447
This theorem is referenced by: (None)
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