Theorem limsuc2 43053

Description: Limit ordinals in the sense inclusive of zero contain all successors of their members. (Contributed by Stefan O'Rear, 20-Jan-2015.)

Assertion

Ref	Expression
limsuc2	⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (𝐵 ∈ 𝐴 ↔ suc 𝐵 ∈ 𝐴))

Proof of Theorem limsuc2

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		ordunisuc2 7865	. . . . 5 ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ↔ ∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴))
2	1	biimpa 476	. . . 4 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → ∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴)
3		suceq 6450	. . . . . 6 ⊢ (𝑥 = 𝐵 → suc 𝑥 = suc 𝐵)
4	3	eleq1d 2826	. . . . 5 ⊢ (𝑥 = 𝐵 → (suc 𝑥 ∈ 𝐴 ↔ suc 𝐵 ∈ 𝐴))
5	4	rspccva 3621	. . . 4 ⊢ ((∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴 ∧ 𝐵 ∈ 𝐴) → suc 𝐵 ∈ 𝐴)
6	2, 5	sylan 580	. . 3 ⊢ (((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) ∧ 𝐵 ∈ 𝐴) → suc 𝐵 ∈ 𝐴)
7	6	ex 412	. 2 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (𝐵 ∈ 𝐴 → suc 𝐵 ∈ 𝐴))
8		ordtr 6398	. . . 4 ⊢ (Ord 𝐴 → Tr 𝐴)
9		trsuc 6471	. . . . 5 ⊢ ((Tr 𝐴 ∧ suc 𝐵 ∈ 𝐴) → 𝐵 ∈ 𝐴)
10	9	ex 412	. . . 4 ⊢ (Tr 𝐴 → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
11	8, 10	syl 17	. . 3 ⊢ (Ord 𝐴 → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
12	11	adantr 480	. 2 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
13	7, 12	impbid 212	1 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (𝐵 ∈ 𝐴 ↔ suc 𝐵 ∈ 𝐴))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1540   ∈ wcel 2108  ∀wral 3061  ∪ cuni 4907  Tr wtr 5259  Ord word 6383  suc csuc 6386

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-ext 2708  ax-sep 5296  ax-nul 5306  ax-pr 5432  ax-un 7755

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3or 1088  df-3an 1089  df-tru 1543  df-fal 1553  df-ex 1780  df-sb 2065  df-clab 2715  df-cleq 2729  df-clel 2816  df-ne 2941  df-ral 3062  df-rex 3071  df-rab 3437  df-v 3482  df-dif 3954  df-un 3956  df-in 3958  df-ss 3968  df-pss 3971  df-nul 4334  df-if 4526  df-pw 4602  df-sn 4627  df-pr 4629  df-op 4633  df-uni 4908  df-br 5144  df-opab 5206  df-tr 5260  df-eprel 5584  df-po 5592  df-so 5593  df-fr 5637  df-we 5639  df-ord 6387  df-on 6388  df-suc 6390

This theorem is referenced by:  aomclem4  43069