Theorem br0 4701

Description: The empty binary relation never holds. (Contributed by NM, 23-Aug-2018.)

Assertion

Ref	Expression
br0	|- -. A (/) B

Proof of Theorem br0

Step	Hyp	Ref	Expression
1		noel 3919	. 2 |- -. <. A , B >. e. (/)
2		df-br 4654	. 2 |- ( A (/) B <-> <. A , B >. e. (/) )
3	1, 2	mtbir 313	1 |- -. A (/) B

Syntax hints:   -. wn 3   e. wcel 1990   (/)c0 3915   <.cop 4183   class class class wbr 4653

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-v 3202  df-dif 3577  df-nul 3916  df-br 4654

This theorem is referenced by:  sbcbr123  4706  sbcbr  4707  cnv0  5535  co02  5649  fvmptopab  6697  brfvopab  6700  0we1  7586  brdom3  9350  canthwe  9473  meet0  17137  join0  17138  brnonrel  37895  upwlkbprop  41719