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Theorem ralsex 17048
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 17047. (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 17037 . 2 (∀∃𝑥𝐴(𝜑𝜓) ↔ (∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑))
2 rexim 2644 . . 3 (∀𝑥𝐴 (𝜑𝜓) → (∃𝑥𝐴 𝜑 → ∃𝑥𝐴 𝜓))
32imp 124 . 2 ((∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑) → ∃𝑥𝐴 𝜓)
41, 3sylbi 121 1 (∀∃𝑥𝐴(𝜑𝜓) → ∃𝑥𝐴 𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104  wral 2528  wrex 2529  ∀∃wrals 17035
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-4 1563  ax-ial 1587
This theorem depends on definitions:  df-bi 117  df-ral 2533  df-rex 2534  df-rals 17037
This theorem is referenced by: (None)
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