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Theorem 0disj 4014
Description: Any collection of empty sets is disjoint. (Contributed by Mario Carneiro, 14-Nov-2016.)
Assertion
Ref Expression
0disj  |- Disj  x  e.  A  (/)

Proof of Theorem 0disj
StepHypRef Expression
1 0ss 3475 . . 3  |-  (/)  C_  { x }
21rgenw 2544 . 2  |-  A. x  e.  A  (/)  C_  { x }
3 sndisj 4013 . 2  |- Disj  x  e.  A  { x }
4 disjss2 3997 . 2  |-  ( A. x  e.  A  (/)  C_  { x }  ->  (Disj  x  e.  A  { x }  -> Disj  x  e.  A  (/) ) )
52, 3, 4mp2 16 1  |- Disj  x  e.  A  (/)
Colors of variables: wff set class
Syntax hints:   A.wral 2467    C_ wss 3143   (/)c0 3436   {csn 3606  Disj wdisj 3994
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-in1 615  ax-in2 616  ax-io 710  ax-5 1457  ax-7 1458  ax-gen 1459  ax-ie1 1503  ax-ie2 1504  ax-8 1514  ax-10 1515  ax-11 1516  ax-i12 1517  ax-bndl 1519  ax-4 1520  ax-17 1536  ax-i9 1540  ax-ial 1544  ax-i5r 1545  ax-ext 2170
This theorem depends on definitions:  df-bi 117  df-tru 1366  df-nf 1471  df-sb 1773  df-eu 2040  df-mo 2041  df-clab 2175  df-cleq 2181  df-clel 2184  df-nfc 2320  df-ral 2472  df-rmo 2475  df-v 2753  df-dif 3145  df-in 3149  df-ss 3156  df-nul 3437  df-sn 3612  df-disj 3995
This theorem is referenced by: (None)
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