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Theorem ssind 3383
Description: A deduction showing that a subclass of two classes is a subclass of their intersection. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.)
Hypotheses
Ref Expression
ssind.1  |-  ( ph  ->  A  C_  B )
ssind.2  |-  ( ph  ->  A  C_  C )
Assertion
Ref Expression
ssind  |-  ( ph  ->  A  C_  ( B  i^i  C ) )

Proof of Theorem ssind
StepHypRef Expression
1 ssind.1 . 2  |-  ( ph  ->  A  C_  B )
2 ssind.2 . 2  |-  ( ph  ->  A  C_  C )
3 ssin 3381 . . 3  |-  ( ( A  C_  B  /\  A  C_  C )  <->  A  C_  ( B  i^i  C ) )
43biimpi 120 . 2  |-  ( ( A  C_  B  /\  A  C_  C )  ->  A  C_  ( B  i^i  C ) )
51, 2, 4syl2anc 411 1  |-  ( ph  ->  A  C_  ( B  i^i  C ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    i^i cin 3152    C_ wss 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 3159  df-ss 3166
This theorem is referenced by:  ntrin  14292  lmss  14414
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