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Theorem reximddv2 2514
Description: Double deduction from Theorem 19.22 of [Margaris] p. 90. (Contributed by Thierry Arnoux, 15-Dec-2019.)
Hypotheses
Ref Expression
reximddv2.1 ((((𝜑𝑥𝐴) ∧ 𝑦𝐵) ∧ 𝜓) → 𝜒)
reximddv2.2 (𝜑 → ∃𝑥𝐴𝑦𝐵 𝜓)
Assertion
Ref Expression
reximddv2 (𝜑 → ∃𝑥𝐴𝑦𝐵 𝜒)
Distinct variable groups:   𝑦,𝐴   𝜑,𝑥,𝑦
Allowed substitution hints:   𝜓(𝑥,𝑦)   𝜒(𝑥,𝑦)   𝐴(𝑥)   𝐵(𝑥,𝑦)

Proof of Theorem reximddv2
StepHypRef Expression
1 reximddv2.1 . . . . 5 ((((𝜑𝑥𝐴) ∧ 𝑦𝐵) ∧ 𝜓) → 𝜒)
21ex 114 . . . 4 (((𝜑𝑥𝐴) ∧ 𝑦𝐵) → (𝜓𝜒))
32reximdva 2511 . . 3 ((𝜑𝑥𝐴) → (∃𝑦𝐵 𝜓 → ∃𝑦𝐵 𝜒))
43impr 376 . 2 ((𝜑 ∧ (𝑥𝐴 ∧ ∃𝑦𝐵 𝜓)) → ∃𝑦𝐵 𝜒)
5 reximddv2.2 . 2 (𝜑 → ∃𝑥𝐴𝑦𝐵 𝜓)
64, 5reximddv 2512 1 (𝜑 → ∃𝑥𝐴𝑦𝐵 𝜒)
Colors of variables: wff set class
Syntax hints:  wi 4  wa 103  wcel 1465  wrex 2394
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1408  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-4 1472  ax-17 1491  ax-ial 1499
This theorem depends on definitions:  df-bi 116  df-nf 1422  df-ral 2398  df-rex 2399
This theorem is referenced by: (None)
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