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Theorem rspc2ev 2686
Description: 2-variable restricted existential specialization, using implicit substitution. (Contributed by NM, 16-Oct-1999.)
Hypotheses
Ref Expression
rspc2v.1 (𝑥 = 𝐴 → (𝜑𝜒))
rspc2v.2 (𝑦 = 𝐵 → (𝜒𝜓))
Assertion
Ref Expression
rspc2ev ((𝐴𝐶𝐵𝐷𝜓) → ∃𝑥𝐶𝑦𝐷 𝜑)
Distinct variable groups:   𝑥,𝑦,𝐴   𝑦,𝐵   𝑥,𝐶   𝑥,𝐷,𝑦   𝜒,𝑥   𝜓,𝑦
Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑥)   𝜒(𝑦)   𝐵(𝑥)   𝐶(𝑦)

Proof of Theorem rspc2ev
StepHypRef Expression
1 rspc2v.2 . . . . 5 (𝑦 = 𝐵 → (𝜒𝜓))
21rspcev 2673 . . . 4 ((𝐵𝐷𝜓) → ∃𝑦𝐷 𝜒)
32anim2i 328 . . 3 ((𝐴𝐶 ∧ (𝐵𝐷𝜓)) → (𝐴𝐶 ∧ ∃𝑦𝐷 𝜒))
433impb 1111 . 2 ((𝐴𝐶𝐵𝐷𝜓) → (𝐴𝐶 ∧ ∃𝑦𝐷 𝜒))
5 rspc2v.1 . . . 4 (𝑥 = 𝐴 → (𝜑𝜒))
65rexbidv 2344 . . 3 (𝑥 = 𝐴 → (∃𝑦𝐷 𝜑 ↔ ∃𝑦𝐷 𝜒))
76rspcev 2673 . 2 ((𝐴𝐶 ∧ ∃𝑦𝐷 𝜒) → ∃𝑥𝐶𝑦𝐷 𝜑)
84, 7syl 14 1 ((𝐴𝐶𝐵𝐷𝜓) → ∃𝑥𝐶𝑦𝐷 𝜑)
Colors of variables: wff set class
Syntax hints:  wi 4  wa 101  wb 102  w3a 896   = wceq 1259  wcel 1409  wrex 2324
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038
This theorem depends on definitions:  df-bi 114  df-3an 898  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-rex 2329  df-v 2576
This theorem is referenced by:  rspc3ev  2688  opelxp  4401  rspceov  5574  2dom  6315  apreim  7667  addcn2  10054  mulcn2  10056
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