Theorem sneqi 3678

Description: Equality inference for singletons. (Contributed by NM, 22-Jan-2004.)

Hypothesis

Ref	Expression
sneqi.1	|- A = B

Assertion

Ref	Expression
sneqi	|- { A } = { B }

Proof of Theorem sneqi

Step	Hyp	Ref	Expression
1		sneqi.1	. 2 |- A = B
2		sneq 3677	. 2 |- ( A = B -> { A } = { B } )
3	1, 2	ax-mp 5	1 |- { A } = { B }

Syntax hints:   = wceq 1395   {csn 3666

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-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-11 1552  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-sn 3672

This theorem is referenced by:  funopsn  5817  fnressn  5825  fressnfv  5826  snriota  5986  xpassen  6989  ennnfonelem1  12978  strle1g  13139  imasplusg  13341  ghmeqker  13808