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Theorem birabrdv 1648
Description: Deduction from wff to restricted class abstraction.
Hypothesis
Ref Expression
birabrdv.1 (φ → (xB → (xAχ)))
Assertion
Ref Expression
birabrdv (φ → (BA) = {xBχ})
Distinct variable group(s):   φ,x   x,A   x,B

Proof of Theorem birabrdv
StepHypRef Expression
1 birabrdv.1 . . . . 5 (φ → (xB → (xAχ)))
21pm5.32d 491 . . . 4 (φ → ((xBxA) ↔ (xBχ)))
3 elin 1635 . . . 4 (x ∈ (BA) ↔ (xBxA))
42, 3syl5bb 410 . . 3 (φ → (x ∈ (BA) ↔ (xBχ)))
54biabrdv 1184 . 2 (φ → (BA) = {x∣(xBχ)})
6 df-rab 1208 . . 3 {xBχ} = {x∣(xBχ)}
76cleqcomi 1105 . 2 {x∣(xBχ)} = {xBχ}
85, 7syl6eq 1140 1 (φ → (BA) = {xBχ})
Colors of variables: wff set class
Syntax hints:   → wi 2   ↔ wb 127   ∧ wa 196  {cab 1090   = wceq 1091   ∈ wcel 1092  {crab 1204   ∩ cin 1486
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-16 922  ax-17 925  ax-ext 1074
This theorem depends on definitions:  df-bi 128  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-rab 1208  df-v 1349  df-in 1491
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