Theorem riotacl2 5968

Description: Membership law for "the unique element in A such that ph."

(Contributed by NM, 21-Aug-2011.) (Revised by Mario Carneiro, 23-Dec-2016.)

Assertion

Ref	Expression
riotacl2	|- ( E! x e. A ph -> ( iota_ x e. A ph ) e. { x e. A | ph } )

Proof of Theorem riotacl2

Step	Hyp	Ref	Expression
1		df-reu 2515	. . 3 |- ( E! x e. A ph <-> E! x ( x e. A /\ ph ) )
2		iotacl 5302	. . 3 |- ( E! x ( x e. A /\ ph ) -> ( iota x ( x e. A /\ ph ) ) e. { x | ( x e. A /\ ph ) } )
3	1, 2	sylbi 121	. 2 |- ( E! x e. A ph -> ( iota x ( x e. A /\ ph ) ) e. { x | ( x e. A /\ ph ) } )
4		df-riota 5953	. 2 |- ( iota_ x e. A ph ) = ( iota x ( x e. A /\ ph ) )
5		df-rab 2517	. 2 |- { x e. A | ph } = { x | ( x e. A /\ ph ) }
6	3, 4, 5	3eltr4g 2315	1 |- ( E! x e. A ph -> ( iota_ x e. A ph ) e. { x e. A | ph } )

Syntax hints:   -> wi 4   /\ wa 104   E!weu 2077   e. wcel 2200   {cab 2215   E!wreu 2510   {crab 2512   iotacio 5275   iota_crio 5952

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-ext 2211

This theorem depends on definitions:  df-bi 117  df-tru 1398  df-nf 1507  df-sb 1809  df-eu 2080  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-rex 2514  df-reu 2515  df-rab 2517  df-v 2801  df-sbc 3029  df-un 3201  df-sn 3672  df-pr 3673  df-uni 3888  df-iota 5277  df-riota 5953

This theorem is referenced by:  riotacl  5969  riotasbc  5970  supubti  7162  suplubti  7163  grplinv  13578