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Theorem ineq1 3353
Description: Equality theorem for intersection of two classes. (Contributed by NM, 14-Dec-1993.)
Assertion
Ref Expression
ineq1  |-  ( A  =  B  ->  ( A  i^i  C )  =  ( B  i^i  C
) )

Proof of Theorem ineq1
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 eleq2 2257 . . . 4  |-  ( A  =  B  ->  (
x  e.  A  <->  x  e.  B ) )
21anbi1d 465 . . 3  |-  ( A  =  B  ->  (
( x  e.  A  /\  x  e.  C
)  <->  ( x  e.  B  /\  x  e.  C ) ) )
3 elin 3342 . . 3  |-  ( x  e.  ( A  i^i  C )  <->  ( x  e.  A  /\  x  e.  C ) )
4 elin 3342 . . 3  |-  ( x  e.  ( B  i^i  C )  <->  ( x  e.  B  /\  x  e.  C ) )
52, 3, 43bitr4g 223 . 2  |-  ( A  =  B  ->  (
x  e.  ( A  i^i  C )  <->  x  e.  ( B  i^i  C ) ) )
65eqrdv 2191 1  |-  ( A  =  B  ->  ( A  i^i  C )  =  ( B  i^i  C
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    = wceq 1364    e. wcel 2164    i^i cin 3152
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 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-v 2762  df-in 3159
This theorem is referenced by:  ineq2  3354  ineq12  3355  ineq1i  3356  ineq1d  3359  dfrab3ss  3437  intprg  3903  inex1g  4165  reseq1  4936  fiintim  6985  uzin2  11131  ressvalsets  12682  elrestr  12858  tgval  12873  inopn  14171  isbasisg  14212  basis1  14215  basis2  14216  ntrfval  14268  tgrest  14337  restco  14342  restsn  14348  restopnb  14349  txrest  14444  metrest  14674  qtopbasss  14689  bdinex1g  15393
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