Theorem treq 5212

Description: Equality theorem for the transitive class predicate. (Contributed by NM, 17-Sep-1993.)

Assertion

Ref	Expression
treq	⊢ (𝐴 = 𝐵 → (Tr 𝐴 ↔ Tr 𝐵))

Proof of Theorem treq

Step	Hyp	Ref	Expression
1		unieq 4874	. . . 4 ⊢ (𝐴 = 𝐵 → ∪ 𝐴 = ∪ 𝐵)
2	1	sseq1d 3965	. . 3 ⊢ (𝐴 = 𝐵 → (∪ 𝐴 ⊆ 𝐴 ↔ ∪ 𝐵 ⊆ 𝐴))
3		sseq2 3960	. . 3 ⊢ (𝐴 = 𝐵 → (∪ 𝐵 ⊆ 𝐴 ↔ ∪ 𝐵 ⊆ 𝐵))
4	2, 3	bitrd 279	. 2 ⊢ (𝐴 = 𝐵 → (∪ 𝐴 ⊆ 𝐴 ↔ ∪ 𝐵 ⊆ 𝐵))
5		df-tr 5206	. 2 ⊢ (Tr 𝐴 ↔ ∪ 𝐴 ⊆ 𝐴)
6		df-tr 5206	. 2 ⊢ (Tr 𝐵 ↔ ∪ 𝐵 ⊆ 𝐵)
7	4, 5, 6	3bitr4g 314	1 ⊢ (𝐴 = 𝐵 → (Tr 𝐴 ↔ Tr 𝐵))

Syntax hints:   → wi 4   ↔ wb 206   = wceq 1541   ⊆ wss 3901  ∪ cuni 4863  Tr wtr 5205

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-ext 2708

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1544  df-ex 1781  df-sb 2068  df-clab 2715  df-cleq 2728  df-clel 2811  df-v 3442  df-ss 3918  df-uni 4864  df-tr 5206

This theorem is referenced by:  truni  5220  trint  5222  ordeq  6324  trcl  9637  tz9.1  9638  tz9.1c  9639  tctr  9647  tcmin  9648  tc2  9649  r1tr  9688  r1elssi  9717  tcrank  9796  iswun  10615  tskr1om2  10679  elgrug  10703  grutsk  10733  tz9.1regs  35290  dfon2lem1  35975  dfon2lem3  35977  dfon2lem4  35978  dfon2lem5  35979  dfon2lem6  35980  dfon2lem7  35981  dfon2lem8  35982  dfon2  35984  exeltr  36665  dford3lem1  43268  dford3lem2  43269  nadd1rabtr  43630  wfaxext  45234  wfaxrep  45235  wfaxpow  45238  wfaxinf2  45242  wfac8prim  45243