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Theorem ineq1 3354
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 3343 . . 3  |-  ( x  e.  ( A  i^i  C )  <->  ( x  e.  A  /\  x  e.  C ) )
4 elin 3343 . . 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 3153
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 3160
This theorem is referenced by:  ineq2  3355  ineq12  3356  ineq1i  3357  ineq1d  3360  dfrab3ss  3438  intprg  3904  inex1g  4166  reseq1  4937  fiintim  6987  uzin2  11134  ressvalsets  12685  elrestr  12861  tgval  12876  inopn  14182  isbasisg  14223  basis1  14226  basis2  14227  ntrfval  14279  tgrest  14348  restco  14353  restsn  14359  restopnb  14360  txrest  14455  metrest  14685  qtopbasss  14700  bdinex1g  15463
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