Theorem bj-tagn0 37469

Description: The tagging of a class is nonempty. (Contributed by BJ, 6-Apr-2019.)

Assertion

Ref	Expression
bj-tagn0	⊢ tag 𝐴 ≠ ∅

Proof of Theorem bj-tagn0

Step	Hyp	Ref	Expression
1		bj-0eltag 37468	. 2 ⊢ ∅ ∈ tag 𝐴
2	1	ne0ii 4298	1 ⊢ tag 𝐴 ≠ ∅

Syntax hints:   ≠ wne 2959  ∅c0 4287  tag bj-ctag 37464

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1817  ax-4 1831  ax-5 1932  ax-6 1989  ax-7 2030  ax-8 2146  ax-9 2154  ax-ext 2736  ax-nul 5258

This theorem depends on definitions:  df-bi 209  df-an 400  df-or 859  df-tru 1565  df-fal 1575  df-ex 1802  df-sb 2093  df-clab 2743  df-cleq 2756  df-clel 2839  df-ne 2960  df-v 3458  df-dif 3909  df-un 3911  df-nul 4288  df-sn 4585  df-bj-tag 37465

This theorem is referenced by:  bj-1upln0  37499  bj-2upln1upl  37514