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Theorem rexim 2413
Description: Theorem 19.22 of [Margaris] p. 90. (Restricted quantifier version.) (Contributed by NM, 22-Nov-1994.) (Proof shortened by Andrew Salmon, 30-May-2011.)
Assertion
Ref Expression
rexim (∀𝑥𝐴 (𝜑𝜓) → (∃𝑥𝐴 𝜑 → ∃𝑥𝐴 𝜓))

Proof of Theorem rexim
StepHypRef Expression
1 df-ral 2311 . . . 4 (∀𝑥𝐴 (𝜑𝜓) ↔ ∀𝑥(𝑥𝐴 → (𝜑𝜓)))
2 simpl 102 . . . . . . 7 ((𝑥𝐴𝜑) → 𝑥𝐴)
32a1i 9 . . . . . 6 ((𝑥𝐴 → (𝜑𝜓)) → ((𝑥𝐴𝜑) → 𝑥𝐴))
4 pm3.31 249 . . . . . 6 ((𝑥𝐴 → (𝜑𝜓)) → ((𝑥𝐴𝜑) → 𝜓))
53, 4jcad 291 . . . . 5 ((𝑥𝐴 → (𝜑𝜓)) → ((𝑥𝐴𝜑) → (𝑥𝐴𝜓)))
65alimi 1344 . . . 4 (∀𝑥(𝑥𝐴 → (𝜑𝜓)) → ∀𝑥((𝑥𝐴𝜑) → (𝑥𝐴𝜓)))
71, 6sylbi 114 . . 3 (∀𝑥𝐴 (𝜑𝜓) → ∀𝑥((𝑥𝐴𝜑) → (𝑥𝐴𝜓)))
8 exim 1490 . . 3 (∀𝑥((𝑥𝐴𝜑) → (𝑥𝐴𝜓)) → (∃𝑥(𝑥𝐴𝜑) → ∃𝑥(𝑥𝐴𝜓)))
97, 8syl 14 . 2 (∀𝑥𝐴 (𝜑𝜓) → (∃𝑥(𝑥𝐴𝜑) → ∃𝑥(𝑥𝐴𝜓)))
10 df-rex 2312 . 2 (∃𝑥𝐴 𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
11 df-rex 2312 . 2 (∃𝑥𝐴 𝜓 ↔ ∃𝑥(𝑥𝐴𝜓))
129, 10, 113imtr4g 194 1 (∀𝑥𝐴 (𝜑𝜓) → (∃𝑥𝐴 𝜑 → ∃𝑥𝐴 𝜓))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 97  wal 1241  wex 1381  wcel 1393  wral 2306  wrex 2307
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-4 1400  ax-ial 1427
This theorem depends on definitions:  df-bi 110  df-ral 2311  df-rex 2312
This theorem is referenced by:  reximia  2414  reximdai  2417  r19.29  2450  reupick2  3223  ss2iun  3672  chfnrn  5278
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