|   | Metamath Proof Explorer | < Previous  
      Next > Nearby theorems | |
| Mirrors > Home > MPE Home > Th. List > ordsssuc2 | Structured version Visualization version GIF version | ||
| Description: An ordinal subset of an ordinal number belongs to its successor. (Contributed by NM, 1-Feb-2005.) (Proof shortened by Andrew Salmon, 12-Aug-2011.) | 
| Ref | Expression | 
|---|---|
| ordsssuc2 | ⊢ ((Ord 𝐴 ∧ 𝐵 ∈ On) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | elong 6391 | . . . . 5 ⊢ (𝐴 ∈ V → (𝐴 ∈ On ↔ Ord 𝐴)) | |
| 2 | 1 | biimprd 248 | . . . 4 ⊢ (𝐴 ∈ V → (Ord 𝐴 → 𝐴 ∈ On)) | 
| 3 | 2 | anim1d 611 | . . 3 ⊢ (𝐴 ∈ V → ((Ord 𝐴 ∧ 𝐵 ∈ On) → (𝐴 ∈ On ∧ 𝐵 ∈ On))) | 
| 4 | onsssuc 6473 | . . 3 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵)) | |
| 5 | 3, 4 | syl6 35 | . 2 ⊢ (𝐴 ∈ V → ((Ord 𝐴 ∧ 𝐵 ∈ On) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵))) | 
| 6 | annim 403 | . . . . 5 ⊢ ((𝐵 ∈ On ∧ ¬ 𝐴 ∈ V) ↔ ¬ (𝐵 ∈ On → 𝐴 ∈ V)) | |
| 7 | ssexg 5322 | . . . . . . 7 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ∈ On) → 𝐴 ∈ V) | |
| 8 | 7 | ex 412 | . . . . . 6 ⊢ (𝐴 ⊆ 𝐵 → (𝐵 ∈ On → 𝐴 ∈ V)) | 
| 9 | elex 3500 | . . . . . . 7 ⊢ (𝐴 ∈ suc 𝐵 → 𝐴 ∈ V) | |
| 10 | 9 | a1d 25 | . . . . . 6 ⊢ (𝐴 ∈ suc 𝐵 → (𝐵 ∈ On → 𝐴 ∈ V)) | 
| 11 | 8, 10 | pm5.21ni 377 | . . . . 5 ⊢ (¬ (𝐵 ∈ On → 𝐴 ∈ V) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵)) | 
| 12 | 6, 11 | sylbi 217 | . . . 4 ⊢ ((𝐵 ∈ On ∧ ¬ 𝐴 ∈ V) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵)) | 
| 13 | 12 | expcom 413 | . . 3 ⊢ (¬ 𝐴 ∈ V → (𝐵 ∈ On → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵))) | 
| 14 | 13 | adantld 490 | . 2 ⊢ (¬ 𝐴 ∈ V → ((Ord 𝐴 ∧ 𝐵 ∈ On) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵))) | 
| 15 | 5, 14 | pm2.61i 182 | 1 ⊢ ((Ord 𝐴 ∧ 𝐵 ∈ On) → (𝐴 ⊆ 𝐵 ↔ 𝐴 ∈ suc 𝐵)) | 
| Colors of variables: wff setvar class | 
| Syntax hints: ¬ wn 3 → wi 4 ↔ wb 206 ∧ wa 395 ∈ wcel 2107 Vcvv 3479 ⊆ wss 3950 Ord word 6382 Oncon0 6383 suc csuc 6385 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-ext 2707 ax-sep 5295 ax-nul 5305 ax-pr 5431 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-sb 2064 df-clab 2714 df-cleq 2728 df-clel 2815 df-ne 2940 df-ral 3061 df-rex 3070 df-rab 3436 df-v 3481 df-dif 3953 df-un 3955 df-in 3957 df-ss 3967 df-pss 3970 df-nul 4333 df-if 4525 df-pw 4601 df-sn 4626 df-pr 4628 df-op 4632 df-uni 4907 df-br 5143 df-opab 5205 df-tr 5259 df-eprel 5583 df-po 5591 df-so 5592 df-fr 5636 df-we 5638 df-ord 6386 df-on 6387 df-suc 6389 | 
| This theorem is referenced by: ordunisuc2 7866 | 
| Copyright terms: Public domain | W3C validator |