Theorem ideq 4781

Description: For sets, the identity relation is the same as equality. (Contributed by NM, 13-Aug-1995.)

Hypothesis

Ref	Expression
ideq.1	⊢ 𝐵 ∈ V

Assertion

Ref	Expression
ideq	⊢ (𝐴 I 𝐵 ↔ 𝐴 = 𝐵)

Proof of Theorem ideq

Step	Hyp	Ref	Expression
1		ideq.1	. 2 ⊢ 𝐵 ∈ V
2		ideqg 4780	. 2 ⊢ (𝐵 ∈ V → (𝐴 I 𝐵 ↔ 𝐴 = 𝐵))
3	1, 2	ax-mp 5	1 ⊢ (𝐴 I 𝐵 ↔ 𝐴 = 𝐵)

Syntax hints:   ↔ wb 105   = wceq 1353   ∈ wcel 2148  Vcvv 2739   class class class wbr 4005   I cid 4290

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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-14 2151  ax-ext 2159  ax-sep 4123  ax-pow 4176  ax-pr 4211

This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-rex 2461  df-v 2741  df-un 3135  df-in 3137  df-ss 3144  df-pw 3579  df-sn 3600  df-pr 3601  df-op 3603  df-br 4006  df-opab 4067  df-id 4295  df-xp 4634  df-rel 4635

This theorem is referenced by:  dmi  4844  resieq  4919  resiexg  4954  iss  4955  restidsing  4965  imai  4986  issref  5013  intasym  5015  asymref  5016  intirr  5017  poirr2  5023  cnvi  5035  coi1  5146  idssen  6779