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Mirrors > Home > MPE Home > Th. List > ssnnfiOLD | Structured version Visualization version GIF version |
Description: Obsolete version of ssnnfi 9192 as of 23-Sep-2024. (Contributed by NM, 24-Jun-1998.) (Proof modification is discouraged.) (New usage is discouraged.) |
Ref | Expression |
---|---|
ssnnfiOLD | ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊆ 𝐴) → 𝐵 ∈ Fin) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sspss 4091 | . . 3 ⊢ (𝐵 ⊆ 𝐴 ↔ (𝐵 ⊊ 𝐴 ∨ 𝐵 = 𝐴)) | |
2 | pssnn 9191 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → ∃𝑥 ∈ 𝐴 𝐵 ≈ 𝑥) | |
3 | elnn 7879 | . . . . . . . . 9 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝐴 ∈ ω) → 𝑥 ∈ ω) | |
4 | 3 | expcom 412 | . . . . . . . 8 ⊢ (𝐴 ∈ ω → (𝑥 ∈ 𝐴 → 𝑥 ∈ ω)) |
5 | 4 | anim1d 609 | . . . . . . 7 ⊢ (𝐴 ∈ ω → ((𝑥 ∈ 𝐴 ∧ 𝐵 ≈ 𝑥) → (𝑥 ∈ ω ∧ 𝐵 ≈ 𝑥))) |
6 | 5 | reximdv2 3154 | . . . . . 6 ⊢ (𝐴 ∈ ω → (∃𝑥 ∈ 𝐴 𝐵 ≈ 𝑥 → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥)) |
7 | 6 | adantr 479 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → (∃𝑥 ∈ 𝐴 𝐵 ≈ 𝑥 → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥)) |
8 | 2, 7 | mpd 15 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) |
9 | eleq1 2813 | . . . . . 6 ⊢ (𝐵 = 𝐴 → (𝐵 ∈ ω ↔ 𝐴 ∈ ω)) | |
10 | 9 | biimparc 478 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 = 𝐴) → 𝐵 ∈ ω) |
11 | enrefnn 9070 | . . . . 5 ⊢ (𝐵 ∈ ω → 𝐵 ≈ 𝐵) | |
12 | breq2 5147 | . . . . . 6 ⊢ (𝑥 = 𝐵 → (𝐵 ≈ 𝑥 ↔ 𝐵 ≈ 𝐵)) | |
13 | 12 | rspcev 3601 | . . . . 5 ⊢ ((𝐵 ∈ ω ∧ 𝐵 ≈ 𝐵) → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) |
14 | 10, 11, 13 | syl2anc2 583 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 = 𝐴) → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) |
15 | 8, 14 | jaodan 955 | . . 3 ⊢ ((𝐴 ∈ ω ∧ (𝐵 ⊊ 𝐴 ∨ 𝐵 = 𝐴)) → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) |
16 | 1, 15 | sylan2b 592 | . 2 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊆ 𝐴) → ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) |
17 | isfi 8995 | . 2 ⊢ (𝐵 ∈ Fin ↔ ∃𝑥 ∈ ω 𝐵 ≈ 𝑥) | |
18 | 16, 17 | sylibr 233 | 1 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊆ 𝐴) → 𝐵 ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 394 ∨ wo 845 = wceq 1533 ∈ wcel 2098 ∃wrex 3060 ⊆ wss 3939 ⊊ wpss 3940 class class class wbr 5143 ωcom 7868 ≈ cen 8959 Fincfn 8962 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-12 2166 ax-ext 2696 ax-sep 5294 ax-nul 5301 ax-pr 5423 ax-un 7738 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-clab 2703 df-cleq 2717 df-clel 2802 df-ne 2931 df-ral 3052 df-rex 3061 df-rab 3420 df-v 3465 df-dif 3942 df-un 3944 df-in 3946 df-ss 3956 df-pss 3959 df-nul 4319 df-if 4525 df-pw 4600 df-sn 4625 df-pr 4627 df-op 4631 df-uni 4904 df-br 5144 df-opab 5206 df-tr 5261 df-id 5570 df-eprel 5576 df-po 5584 df-so 5585 df-fr 5627 df-we 5629 df-xp 5678 df-rel 5679 df-cnv 5680 df-co 5681 df-dm 5682 df-rn 5683 df-ord 6367 df-on 6368 df-lim 6369 df-suc 6370 df-fun 6545 df-fn 6546 df-f 6547 df-f1 6548 df-fo 6549 df-f1o 6550 df-om 7869 df-en 8963 df-fin 8966 |
This theorem is referenced by: (None) |
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