Theorem opeldmg 4961

Description: Membership of first of an ordered pair in a domain. (Contributed by Jim Kingdon, 9-Jul-2019.)

Assertion

Ref	Expression
opeldmg	|- ( ( A e. V /\ B e. W ) -> ( <. A , B >. e. C -> A e. dom C ) )

Proof of Theorem opeldmg

Dummy variable y is distinct from all other variables.

Step	Hyp	Ref	Expression
1		opeq2 3884	. . . . 5 |- ( y = B -> <. A , y >. = <. A , B >. )
2	1	eleq1d 2301	. . . 4 |- ( y = B -> ( <. A , y >. e. C <-> <. A , B >. e. C ) )
3	2	spcegv 2905	. . 3 |- ( B e. W -> ( <. A , B >. e. C -> E. y <. A , y >. e. C ) )
4	3	adantl 277	. 2 |- ( ( A e. V /\ B e. W ) -> ( <. A , B >. e. C -> E. y <. A , y >. e. C ) )
5		eldm2g 4952	. . 3 |- ( A e. V -> ( A e. dom C <-> E. y <. A , y >. e. C ) )
6	5	adantr 276	. 2 |- ( ( A e. V /\ B e. W ) -> ( A e. dom C <-> E. y <. A , y >. e. C ) )
7	4, 6	sylibrd 169	1 |- ( ( A e. V /\ B e. W ) -> ( <. A , B >. e. C -> A e. dom C ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1398   E.wex 1541   e. wcel 2203   <.cop 3692   dom cdm 4749

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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2214

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-v 2815  df-un 3215  df-sn 3695  df-pr 3696  df-op 3698  df-br 4110  df-dm 4759

This theorem is referenced by:  tfr0dm  6553  tfrlemi14d  6564  tfr1onlemres  6580  tfrcllemres  6593  fnfi  7203  frecuzrdgtcl  10774  frecuzrdgdomlem  10779  hashennn  11143  imasaddfnlemg  13527