Theorem uneq1i 3331

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

Hypothesis

Ref	Expression
uneq1i.1	|- A = B

Assertion

Ref	Expression
uneq1i	|- ( A u. C ) = ( B u. C )

Proof of Theorem uneq1i

Step	Hyp	Ref	Expression
1		uneq1i.1	. 2 |- A = B
2		uneq1 3328	. 2 |- ( A = B -> ( A u. C ) = ( B u. C ) )
3	1, 2	ax-mp 5	1 |- ( A u. C ) = ( B u. C )

Syntax hints:   = wceq 1373   u. cun 3172

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-v 2778  df-un 3178

This theorem is referenced by:  un12  3339  unundi  3342  tpcoma  3737  qdass  3740  qdassr  3741  tpidm12  3742  resasplitss  5477  fmptpr  5799  df2o3  6539  undifdc  7047  sbthlemi6  7090  exmidfodomrlemim  7340  znnen  12884  setscom  12987