Theorem erth2 6727

Description: Basic property of equivalence relations. Compare Theorem 73 of [Suppes] p. 82. Assumes membership of the second argument in the domain. (Contributed by NM, 30-Jul-1995.) (Revised by Mario Carneiro, 6-Jul-2015.)

Hypotheses

Ref	Expression
erth2.1	|- ( ph -> R Er X )
erth2.2	|- ( ph -> B e. X )

Assertion

Ref	Expression
erth2	|- ( ph -> ( A R B <-> [ A ] R = [ B ] R ) )

Proof of Theorem erth2

Step	Hyp	Ref	Expression
1		erth2.1	. . 3 |- ( ph -> R Er X )
2	1	ersymb 6694	. 2 |- ( ph -> ( A R B <-> B R A ) )
3		erth2.2	. . . 4 |- ( ph -> B e. X )
4	1, 3	erth 6726	. . 3 |- ( ph -> ( B R A <-> [ B ] R = [ A ] R ) )
5		eqcom 2231	. . 3 |- ( [ B ] R = [ A ] R <-> [ A ] R = [ B ] R )
6	4, 5	bitrdi 196	. 2 |- ( ph -> ( B R A <-> [ A ] R = [ B ] R ) )
7	2, 6	bitrd 188	1 |- ( ph -> ( A R B <-> [ A ] R = [ B ] R ) )

Syntax hints:   -> wi 4   <-> wb 105   = wceq 1395   e. wcel 2200   class class class wbr 4083   Er wer 6677   [cec 6678

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-14 2203  ax-ext 2211  ax-sep 4202  ax-pow 4258  ax-pr 4293

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-v 2801  df-sbc 3029  df-un 3201  df-in 3203  df-ss 3210  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-br 4084  df-opab 4146  df-xp 4725  df-rel 4726  df-cnv 4727  df-co 4728  df-dm 4729  df-rn 4730  df-res 4731  df-ima 4732  df-er 6680  df-ec 6682

This theorem is referenced by:  qliftel  6762