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Theorem iotabi 4819
 Description: Equivalence theorem for descriptions. (Contributed by Andrew Salmon, 30-Jun-2011.)
Assertion
Ref Expression
iotabi

Proof of Theorem iotabi
Dummy variable is distinct from all other variables.
StepHypRef Expression
1 abbi 2148 . . . . . 6
21biimpi 113 . . . . 5
32eqeq1d 2045 . . . 4
43abbidv 2152 . . 3
54unieqd 3582 . 2
6 df-iota 4810 . 2
7 df-iota 4810 . 2
85, 6, 73eqtr4g 2094 1
 Colors of variables: wff set class Syntax hints:   wi 4   wb 98  wal 1240   wceq 1242  cab 2023  csn 3367  cuni 3571  cio 4808 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-io 629  ax-5 1333  ax-7 1334  ax-gen 1335  ax-ie1 1379  ax-ie2 1380  ax-8 1392  ax-10 1393  ax-11 1394  ax-i12 1395  ax-bndl 1396  ax-4 1397  ax-17 1416  ax-i9 1420  ax-ial 1424  ax-i5r 1425  ax-ext 2019 This theorem depends on definitions:  df-bi 110  df-tru 1245  df-nf 1347  df-sb 1643  df-clab 2024  df-cleq 2030  df-clel 2033  df-nfc 2164  df-rex 2306  df-uni 3572  df-iota 4810 This theorem is referenced by:  iotabidv  4831  iotabii  4832  eusvobj1  5442
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