Theorem ordsucg 4626

Description: The successor of an ordinal class is ordinal. (Contributed by Jim Kingdon, 20-Nov-2018.)

Assertion

Ref	Expression
ordsucg	⊢ (𝐴 ∈ V → (Ord 𝐴 ↔ Ord suc 𝐴))

Proof of Theorem ordsucg

Step	Hyp	Ref	Expression
1		ordsucim 4624	. 2 ⊢ (Ord 𝐴 → Ord suc 𝐴)
2		sucidg 4539	. . 3 ⊢ (𝐴 ∈ V → 𝐴 ∈ suc 𝐴)
3		ordelord 4504	. . . 4 ⊢ ((Ord suc 𝐴 ∧ 𝐴 ∈ suc 𝐴) → Ord 𝐴)
4	3	ex 115	. . 3 ⊢ (Ord suc 𝐴 → (𝐴 ∈ suc 𝐴 → Ord 𝐴))
5	2, 4	syl5com 29	. 2 ⊢ (𝐴 ∈ V → (Ord suc 𝐴 → Ord 𝐴))
6	1, 5	impbid2 143	1 ⊢ (𝐴 ∈ V → (Ord 𝐴 ↔ Ord suc 𝐴))

Syntax hints:   → wi 4   ↔ wb 105   ∈ wcel 2205  Vcvv 2815  Ord word 4485  suc csuc 4488

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2216

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ral 2527  df-rex 2528  df-v 2817  df-un 3217  df-in 3219  df-ss 3226  df-sn 3697  df-uni 3917  df-tr 4211  df-iord 4489  df-suc 4494

This theorem is referenced by:  onsucb  4627