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Theorem disjx0 4014
Description: An empty collection is disjoint. (Contributed by Mario Carneiro, 14-Nov-2016.)
Assertion
Ref Expression
disjx0  |- Disj  x  e.  (/)  B

Proof of Theorem disjx0
StepHypRef Expression
1 0ss 3473 . 2  |-  (/)  C_  { (/) }
2 disjxsn 4013 . 2  |- Disj  x  e. 
{ (/) } B
3 disjss1 3998 . 2  |-  ( (/)  C_ 
{ (/) }  ->  (Disj  x  e.  { (/) } B  -> Disj  x  e.  (/)  B ) )
41, 2, 3mp2 16 1  |- Disj  x  e.  (/)  B
Colors of variables: wff set class
Syntax hints:    C_ wss 3141   (/)c0 3434   {csn 3604  Disj wdisj 3992
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 2169
This theorem depends on definitions:  df-bi 117  df-tru 1366  df-nf 1471  df-sb 1773  df-eu 2039  df-mo 2040  df-clab 2174  df-cleq 2180  df-clel 2183  df-nfc 2318  df-rmo 2473  df-v 2751  df-dif 3143  df-in 3147  df-ss 3154  df-nul 3435  df-sn 3610  df-disj 3993
This theorem is referenced by: (None)
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