Theorem dfdm4 4914

Description: Alternate definition of domain. (Contributed by NM, 28-Dec-1996.)

Assertion

Ref	Expression
dfdm4	⊢ dom 𝐴 = ran ◡𝐴

Proof of Theorem dfdm4

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		vex 2802	. . . . 5 ⊢ 𝑦 ∈ V
2		vex 2802	. . . . 5 ⊢ 𝑥 ∈ V
3	1, 2	brcnv 4904	. . . 4 ⊢ (𝑦◡𝐴𝑥 ↔ 𝑥𝐴𝑦)
4	3	exbii 1651	. . 3 ⊢ (∃𝑦 𝑦◡𝐴𝑥 ↔ ∃𝑦 𝑥𝐴𝑦)
5	4	abbii 2345	. 2 ⊢ {𝑥 ∣ ∃𝑦 𝑦◡𝐴𝑥} = {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦}
6		dfrn2 4909	. 2 ⊢ ran ◡𝐴 = {𝑥 ∣ ∃𝑦 𝑦◡𝐴𝑥}
7		df-dm 4728	. 2 ⊢ dom 𝐴 = {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦}
8	5, 6, 7	3eqtr4ri 2261	1 ⊢ dom 𝐴 = ran ◡𝐴

Syntax hints:   = wceq 1395  ∃wex 1538  {cab 2215   class class class wbr 4082  ^◡ccnv 4717  dom cdm 4718  ran crn 4719

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 4201  ax-pow 4257  ax-pr 4292

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-v 2801  df-un 3201  df-in 3203  df-ss 3210  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-br 4083  df-opab 4145  df-cnv 4726  df-dm 4728  df-rn 4729

This theorem is referenced by:  dmcnvcnv  4947  rncnvcnv  4948  rncoeq  4997  cnvimass  5090  cnvimarndm  5091  dminxp  5172  cnvsn0  5196  rnsnopg  5206  dmmpt  5223  dmco  5236  cores2  5240  cnvssrndm  5249  cocnvres  5252  unidmrn  5260  dfdm2  5262  cnvexg  5265  funimacnv  5396  foimacnv  5589  funcocnv2  5596  fimacnv  5763  f1opw2  6210  fopwdom  6993  sbthlemi4  7123  exmidfodomrlemim  7375  hmeores  14983