Theorem iuneq2i 3959

Description: Equality inference for indexed union. (Contributed by NM, 22-Oct-2003.)

Hypothesis

Ref	Expression
iuneq2i.1	|- ( x e. A -> B = C )

Assertion

Ref	Expression
iuneq2i	|- U_ x e. A B = U_ x e. A C

Proof of Theorem iuneq2i

Step	Hyp	Ref	Expression
1		iuneq2 3957	. 2 |- ( A. x e. A B = C -> U_ x e. A B = U_ x e. A C )
2		iuneq2i.1	. 2 |- ( x e. A -> B = C )
3	1, 2	mprg 2565	1 |- U_ x e. A B = U_ x e. A C

Syntax hints:   -> wi 4   = wceq 1373   e. wcel 2178   U_ciun 3941

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2189

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-ral 2491  df-rex 2492  df-v 2778  df-in 3180  df-ss 3187  df-iun 3943

This theorem is referenced by:  dfiunv2  3977  iunrab  3989  iunid  3997  iunin1  4006  2iunin  4008  resiun1  4997  resiun2  4998  dfimafn2  5651  dfmpt  5780  rdgival  6491  uniqs  6703  imasplusg  13255  txbasval  14854