Theorem unieqi 3898

Description: Inference of equality of two class unions. (Contributed by NM, 30-Aug-1993.)

Hypothesis

Ref	Expression
unieqi.1	|- A = B

Assertion

Ref	Expression
unieqi	|- U. A = U. B

Proof of Theorem unieqi

Step	Hyp	Ref	Expression
1		unieqi.1	. 2 |- A = B
2		unieq 3897	. 2 |- ( A = B -> U. A = U. B )
3	1, 2	ax-mp 5	1 |- U. A = U. B

Syntax hints:   = wceq 1395   U.cuni 3888

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 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-ext 2211

This theorem depends on definitions:  df-bi 117  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-rex 2514  df-uni 3889

This theorem is referenced by:  elunirab  3901  unisn  3904  uniop  4342  unisuc  4504  unisucg  4505  univ  4567  dfiun3g  4981  op1sta  5210  op2nda  5213  dfdm2  5263  iotajust  5277  dfiota2  5279  cbviota  5283  cbviotavw  5284  sb8iota  5286  dffv4g  5626  funfvdm2f  5701  riotauni  5967  1st0  6296  2nd0  6297  unielxp  6326  brtpos0  6404  recsfval  6467  uniqs  6748  xpassen  6997  sup00  7178  suplocexprlemell  7908  uptx  14956