Theorem uneq2i 3380

Description: Inference adding union to the left in a class equality. (Contributed by NM, 30-Aug-1993.)

Hypothesis

Ref	Expression
uneq1i.1	|- A = B

Assertion

Ref	Expression
uneq2i	|- ( C u. A ) = ( C u. B )

Proof of Theorem uneq2i

Step	Hyp	Ref	Expression
1		uneq1i.1	. 2 |- A = B
2		uneq2 3377	. 2 |- ( A = B -> ( C u. A ) = ( C u. B ) )
3	1, 2	ax-mp 5	1 |- ( C u. A ) = ( C u. B )

Syntax hints:   = wceq 1402   u. cun 3218

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 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-v 2823  df-un 3224

This theorem is referenced by:  un4  3389  unundir  3391  difun2  3604  difdifdirss  3609  if0ab  3638  qdass  3804  qdassr  3805  unisuc  4553  iunsuc  4560  fmptap  5896  fvsnun1  5903  rdgival  6643  rdg0  6648  undifdc  7221  exmidfodomrlemim  7543  djuassen  7563  facnn  11143  fac0  11144  fsum2dlemstep  12179  fsumiun  12222  fprod2dlemstep  12367  plyun0  15760  lgsquadlem3  16112