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Theorem tsk1 8386
Description: One is an element of a non empty Tarski's class. (Contributed by FL, 22-Feb-2011.)
Assertion
Ref Expression
tsk1  |-  ( ( T  e.  Tarski  /\  T  =/=  (/) )  ->  1o  e.  T )

Proof of Theorem tsk1
StepHypRef Expression
1 df1o2 6491 . 2  |-  1o  =  { (/) }
2 tsk0 8385 . . 3  |-  ( ( T  e.  Tarski  /\  T  =/=  (/) )  ->  (/)  e.  T
)
3 tsksn 8382 . . 3  |-  ( ( T  e.  Tarski  /\  (/)  e.  T
)  ->  { (/) }  e.  T )
42, 3syldan 456 . 2  |-  ( ( T  e.  Tarski  /\  T  =/=  (/) )  ->  { (/) }  e.  T )
51, 4syl5eqel 2367 1  |-  ( ( T  e.  Tarski  /\  T  =/=  (/) )  ->  1o  e.  T )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 358    e. wcel 1684    =/= wne 2446   (/)c0 3455   {csn 3640   1oc1o 6472   Tarskictsk 8370
This theorem is referenced by:  tsk2  8387
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1533  ax-5 1544  ax-17 1603  ax-9 1635  ax-8 1643  ax-14 1688  ax-6 1703  ax-7 1708  ax-11 1715  ax-12 1866  ax-ext 2264  ax-sep 4141  ax-pow 4188
This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3an 936  df-tru 1310  df-ex 1529  df-nf 1532  df-sb 1630  df-clab 2270  df-cleq 2276  df-clel 2279  df-nfc 2408  df-ne 2448  df-ral 2548  df-rex 2549  df-rab 2552  df-v 2790  df-dif 3155  df-un 3157  df-in 3159  df-ss 3166  df-nul 3456  df-if 3566  df-pw 3627  df-sn 3646  df-pr 3647  df-op 3649  df-br 4024  df-suc 4398  df-1o 6479  df-tsk 8371
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