Theorem limsuc2 43486

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 7784	. . . . 5 ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ↔ ∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴))
2	1	biimpa 477	. . . 4 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → ∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴)
3		suceq 6378	. . . . . 6 ⊢ (𝑥 = 𝐵 → suc 𝑥 = suc 𝐵)
4	3	eleq1d 2824	. . . . 5 ⊢ (𝑥 = 𝐵 → (suc 𝑥 ∈ 𝐴 ↔ suc 𝐵 ∈ 𝐴))
5	4	rspccva 3559	. . . 4 ⊢ ((∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴 ∧ 𝐵 ∈ 𝐴) → suc 𝐵 ∈ 𝐴)
6	2, 5	sylan 586	. . 3 ⊢ (((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) ∧ 𝐵 ∈ 𝐴) → suc 𝐵 ∈ 𝐴)
7	6	ex 413	. 2 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (𝐵 ∈ 𝐴 → suc 𝐵 ∈ 𝐴))
8		ordtr 6324	. . . 4 ⊢ (Ord 𝐴 → Tr 𝐴)
9		trsuc 6399	. . . . 5 ⊢ ((Tr 𝐴 ∧ suc 𝐵 ∈ 𝐴) → 𝐵 ∈ 𝐴)
10	9	ex 413	. . . 4 ⊢ (Tr 𝐴 → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
11	8, 10	syl 17	. . 3 ⊢ (Ord 𝐴 → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
12	11	adantr 481	. 2 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (suc 𝐵 ∈ 𝐴 → 𝐵 ∈ 𝐴))
13	7, 12	impbid 213	1 ⊢ ((Ord 𝐴 ∧ 𝐴 = ∪ 𝐴) → (𝐵 ∈ 𝐴 ↔ suc 𝐵 ∈ 𝐴))

Syntax hints:   → wi 4   ↔ wb 207   ∧ wa 396   = wceq 1547   ∈ wcel 2119  ∀wral 3053  ∪ cuni 4838  Tr wtr 5179  Ord word 6309  suc csuc 6312

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-ext 2711  ax-sep 5218  ax-nul 5228  ax-pr 5362  ax-un 7678

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3or 1093  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-sb 2074  df-clab 2718  df-cleq 2731  df-clel 2814  df-ne 2935  df-ral 3054  df-rex 3064  df-rab 3392  df-v 3433  df-dif 3886  df-un 3888  df-in 3890  df-ss 3900  df-pss 3903  df-nul 4262  df-if 4455  df-pw 4531  df-sn 4556  df-pr 4558  df-op 4562  df-uni 4839  df-br 5073  df-opab 5135  df-tr 5180  df-eprel 5518  df-po 5526  df-so 5527  df-fr 5571  df-we 5573  df-ord 6313  df-on 6314  df-suc 6316

This theorem is referenced by:  aomclem4  43502