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Theorem ssnn0fi 12646
 Description: A subset of the nonnegative integers is finite if and only if there is a nonnegative integer so that all integers greater than this integer are not contained in the subset. (Contributed by AV, 3-Oct-2019.)
Assertion
Ref Expression
ssnn0fi (𝑆 ⊆ ℕ0 → (𝑆 ∈ Fin ↔ ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
Distinct variable group:   𝑆,𝑠,𝑥

Proof of Theorem ssnn0fi
Dummy variables 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 0nn0 11184 . . . . . 6 0 ∈ ℕ0
21a1i 11 . . . . 5 (𝑆 = ∅ → 0 ∈ ℕ0)
3 breq1 4586 . . . . . . . 8 (𝑠 = 0 → (𝑠 < 𝑥 ↔ 0 < 𝑥))
43imbi1d 330 . . . . . . 7 (𝑠 = 0 → ((𝑠 < 𝑥𝑥𝑆) ↔ (0 < 𝑥𝑥𝑆)))
54ralbidv 2969 . . . . . 6 (𝑠 = 0 → (∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) ↔ ∀𝑥 ∈ ℕ0 (0 < 𝑥𝑥𝑆)))
65adantl 481 . . . . 5 ((𝑆 = ∅ ∧ 𝑠 = 0) → (∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) ↔ ∀𝑥 ∈ ℕ0 (0 < 𝑥𝑥𝑆)))
7 nnel 2892 . . . . . . . . 9 𝑥𝑆𝑥𝑆)
8 n0i 3879 . . . . . . . . 9 (𝑥𝑆 → ¬ 𝑆 = ∅)
97, 8sylbi 206 . . . . . . . 8 𝑥𝑆 → ¬ 𝑆 = ∅)
109con4i 112 . . . . . . 7 (𝑆 = ∅ → 𝑥𝑆)
1110a1d 25 . . . . . 6 (𝑆 = ∅ → (0 < 𝑥𝑥𝑆))
1211ralrimivw 2950 . . . . 5 (𝑆 = ∅ → ∀𝑥 ∈ ℕ0 (0 < 𝑥𝑥𝑆))
132, 6, 12rspcedvd 3289 . . . 4 (𝑆 = ∅ → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))
14132a1d 26 . . 3 (𝑆 = ∅ → (𝑆 ⊆ ℕ0 → (𝑆 ∈ Fin → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))))
15 ltso 9997 . . . . . . 7 < Or ℝ
16 id 22 . . . . . . . . 9 (𝑆 ⊆ ℕ0𝑆 ⊆ ℕ0)
17 nn0ssre 11173 . . . . . . . . 9 0 ⊆ ℝ
1816, 17syl6ss 3580 . . . . . . . 8 (𝑆 ⊆ ℕ0𝑆 ⊆ ℝ)
19183anim3i 1243 . . . . . . 7 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → (𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℝ))
20 fisup2g 8257 . . . . . . 7 (( < Or ℝ ∧ (𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℝ)) → ∃𝑠𝑆 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)))
2115, 19, 20sylancr 694 . . . . . 6 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → ∃𝑠𝑆 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)))
22 simp3 1056 . . . . . . 7 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → 𝑆 ⊆ ℕ0)
23 breq2 4587 . . . . . . . . . . . . . . . . . . . 20 (𝑦 = 𝑥 → (𝑠 < 𝑦𝑠 < 𝑥))
2423notbid 307 . . . . . . . . . . . . . . . . . . 19 (𝑦 = 𝑥 → (¬ 𝑠 < 𝑦 ↔ ¬ 𝑠 < 𝑥))
2524rspcva 3280 . . . . . . . . . . . . . . . . . 18 ((𝑥𝑆 ∧ ∀𝑦𝑆 ¬ 𝑠 < 𝑦) → ¬ 𝑠 < 𝑥)
26252a1d 26 . . . . . . . . . . . . . . . . 17 ((𝑥𝑆 ∧ ∀𝑦𝑆 ¬ 𝑠 < 𝑦) → (𝑥 ∈ ℕ0 → (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → ¬ 𝑠 < 𝑥)))
2726expcom 450 . . . . . . . . . . . . . . . 16 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 → (𝑥𝑆 → (𝑥 ∈ ℕ0 → (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → ¬ 𝑠 < 𝑥))))
2827com24 93 . . . . . . . . . . . . . . 15 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 → (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → (𝑥 ∈ ℕ0 → (𝑥𝑆 → ¬ 𝑠 < 𝑥))))
2928imp31 447 . . . . . . . . . . . . . 14 (((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆)) ∧ 𝑥 ∈ ℕ0) → (𝑥𝑆 → ¬ 𝑠 < 𝑥))
307, 29syl5bi 231 . . . . . . . . . . . . 13 (((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆)) ∧ 𝑥 ∈ ℕ0) → (¬ 𝑥𝑆 → ¬ 𝑠 < 𝑥))
3130con4d 113 . . . . . . . . . . . 12 (((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆)) ∧ 𝑥 ∈ ℕ0) → (𝑠 < 𝑥𝑥𝑆))
3231ralrimiva 2949 . . . . . . . . . . 11 ((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆)) → ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))
3332ex 449 . . . . . . . . . 10 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 → (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
3433adantr 480 . . . . . . . . 9 ((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)) → (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
3534com12 32 . . . . . . . 8 (((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) ∧ 𝑠𝑆) → ((∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)) → ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
3635reximdva 3000 . . . . . . 7 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → (∃𝑠𝑆 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)) → ∃𝑠𝑆𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
37 ssrexv 3630 . . . . . . 7 (𝑆 ⊆ ℕ0 → (∃𝑠𝑆𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
3822, 36, 37sylsyld 59 . . . . . 6 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → (∃𝑠𝑆 (∀𝑦𝑆 ¬ 𝑠 < 𝑦 ∧ ∀𝑦 ∈ ℝ (𝑦 < 𝑠 → ∃𝑧𝑆 𝑦 < 𝑧)) → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
3921, 38mpd 15 . . . . 5 ((𝑆 ∈ Fin ∧ 𝑆 ≠ ∅ ∧ 𝑆 ⊆ ℕ0) → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))
40393exp 1256 . . . 4 (𝑆 ∈ Fin → (𝑆 ≠ ∅ → (𝑆 ⊆ ℕ0 → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))))
4140com3l 87 . . 3 (𝑆 ≠ ∅ → (𝑆 ⊆ ℕ0 → (𝑆 ∈ Fin → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆))))
4214, 41pm2.61ine 2865 . 2 (𝑆 ⊆ ℕ0 → (𝑆 ∈ Fin → ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
43 fzfi 12633 . . . . 5 (0...𝑠) ∈ Fin
44 elfz2nn0 12300 . . . . . . . . . . 11 (𝑦 ∈ (0...𝑠) ↔ (𝑦 ∈ ℕ0𝑠 ∈ ℕ0𝑦𝑠))
4544notbii 309 . . . . . . . . . 10 𝑦 ∈ (0...𝑠) ↔ ¬ (𝑦 ∈ ℕ0𝑠 ∈ ℕ0𝑦𝑠))
46 3ianor 1048 . . . . . . . . . 10 (¬ (𝑦 ∈ ℕ0𝑠 ∈ ℕ0𝑦𝑠) ↔ (¬ 𝑦 ∈ ℕ0 ∨ ¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠))
47 3orass 1034 . . . . . . . . . 10 ((¬ 𝑦 ∈ ℕ0 ∨ ¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠) ↔ (¬ 𝑦 ∈ ℕ0 ∨ (¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠)))
4845, 46, 473bitri 285 . . . . . . . . 9 𝑦 ∈ (0...𝑠) ↔ (¬ 𝑦 ∈ ℕ0 ∨ (¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠)))
49 ssel 3562 . . . . . . . . . . . . 13 (𝑆 ⊆ ℕ0 → (𝑦𝑆𝑦 ∈ ℕ0))
5049adantr 480 . . . . . . . . . . . 12 ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (𝑦𝑆𝑦 ∈ ℕ0))
5150adantr 480 . . . . . . . . . . 11 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (𝑦𝑆𝑦 ∈ ℕ0))
5251con3rr3 150 . . . . . . . . . 10 𝑦 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆))
53 notnotb 303 . . . . . . . . . . . 12 (𝑦 ∈ ℕ0 ↔ ¬ ¬ 𝑦 ∈ ℕ0)
54 pm2.24 120 . . . . . . . . . . . . . . . . 17 (𝑠 ∈ ℕ0 → (¬ 𝑠 ∈ ℕ0 → ¬ 𝑦𝑆))
5554adantl 481 . . . . . . . . . . . . . . . 16 ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (¬ 𝑠 ∈ ℕ0 → ¬ 𝑦𝑆))
5655adantr 480 . . . . . . . . . . . . . . 15 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (¬ 𝑠 ∈ ℕ0 → ¬ 𝑦𝑆))
5756com12 32 . . . . . . . . . . . . . 14 𝑠 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆))
5857a1d 25 . . . . . . . . . . . . 13 𝑠 ∈ ℕ0 → (𝑦 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆)))
59 breq2 4587 . . . . . . . . . . . . . . . . . . . 20 (𝑥 = 𝑦 → (𝑠 < 𝑥𝑠 < 𝑦))
60 neleq1 2888 . . . . . . . . . . . . . . . . . . . 20 (𝑥 = 𝑦 → (𝑥𝑆𝑦𝑆))
6159, 60imbi12d 333 . . . . . . . . . . . . . . . . . . 19 (𝑥 = 𝑦 → ((𝑠 < 𝑥𝑥𝑆) ↔ (𝑠 < 𝑦𝑦𝑆)))
6261rspcva 3280 . . . . . . . . . . . . . . . . . 18 ((𝑦 ∈ ℕ0 ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (𝑠 < 𝑦𝑦𝑆))
63 nn0re 11178 . . . . . . . . . . . . . . . . . . . . . . . . 25 (𝑠 ∈ ℕ0𝑠 ∈ ℝ)
64 nn0re 11178 . . . . . . . . . . . . . . . . . . . . . . . . 25 (𝑦 ∈ ℕ0𝑦 ∈ ℝ)
65 ltnle 9996 . . . . . . . . . . . . . . . . . . . . . . . . 25 ((𝑠 ∈ ℝ ∧ 𝑦 ∈ ℝ) → (𝑠 < 𝑦 ↔ ¬ 𝑦𝑠))
6663, 64, 65syl2an 493 . . . . . . . . . . . . . . . . . . . . . . . 24 ((𝑠 ∈ ℕ0𝑦 ∈ ℕ0) → (𝑠 < 𝑦 ↔ ¬ 𝑦𝑠))
67 df-nel 2783 . . . . . . . . . . . . . . . . . . . . . . . . 25 (𝑦𝑆 ↔ ¬ 𝑦𝑆)
6867a1i 11 . . . . . . . . . . . . . . . . . . . . . . . 24 ((𝑠 ∈ ℕ0𝑦 ∈ ℕ0) → (𝑦𝑆 ↔ ¬ 𝑦𝑆))
6966, 68imbi12d 333 . . . . . . . . . . . . . . . . . . . . . . 23 ((𝑠 ∈ ℕ0𝑦 ∈ ℕ0) → ((𝑠 < 𝑦𝑦𝑆) ↔ (¬ 𝑦𝑠 → ¬ 𝑦𝑆)))
7069biimpd 218 . . . . . . . . . . . . . . . . . . . . . 22 ((𝑠 ∈ ℕ0𝑦 ∈ ℕ0) → ((𝑠 < 𝑦𝑦𝑆) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆)))
7170ex 449 . . . . . . . . . . . . . . . . . . . . 21 (𝑠 ∈ ℕ0 → (𝑦 ∈ ℕ0 → ((𝑠 < 𝑦𝑦𝑆) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7271adantl 481 . . . . . . . . . . . . . . . . . . . 20 ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (𝑦 ∈ ℕ0 → ((𝑠 < 𝑦𝑦𝑆) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7372com12 32 . . . . . . . . . . . . . . . . . . 19 (𝑦 ∈ ℕ0 → ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → ((𝑠 < 𝑦𝑦𝑆) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7473adantr 480 . . . . . . . . . . . . . . . . . 18 ((𝑦 ∈ ℕ0 ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → ((𝑠 < 𝑦𝑦𝑆) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7562, 74mpid 43 . . . . . . . . . . . . . . . . 17 ((𝑦 ∈ ℕ0 ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆)))
7675ex 449 . . . . . . . . . . . . . . . 16 (𝑦 ∈ ℕ0 → (∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) → ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7776com13 86 . . . . . . . . . . . . . . 15 ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) → (𝑦 ∈ ℕ0 → (¬ 𝑦𝑠 → ¬ 𝑦𝑆))))
7877imp 444 . . . . . . . . . . . . . 14 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (𝑦 ∈ ℕ0 → (¬ 𝑦𝑠 → ¬ 𝑦𝑆)))
7978com13 86 . . . . . . . . . . . . 13 𝑦𝑠 → (𝑦 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆)))
8058, 79jaoi 393 . . . . . . . . . . . 12 ((¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠) → (𝑦 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆)))
8153, 80syl5bir 232 . . . . . . . . . . 11 ((¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠) → (¬ ¬ 𝑦 ∈ ℕ0 → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆)))
8281impcom 445 . . . . . . . . . 10 ((¬ ¬ 𝑦 ∈ ℕ0 ∧ (¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠)) → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆))
8352, 82jaoi3 1003 . . . . . . . . 9 ((¬ 𝑦 ∈ ℕ0 ∨ (¬ 𝑠 ∈ ℕ0 ∨ ¬ 𝑦𝑠)) → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆))
8448, 83sylbi 206 . . . . . . . 8 𝑦 ∈ (0...𝑠) → (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → ¬ 𝑦𝑆))
8584com12 32 . . . . . . 7 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (¬ 𝑦 ∈ (0...𝑠) → ¬ 𝑦𝑆))
8685con4d 113 . . . . . 6 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → (𝑦𝑆𝑦 ∈ (0...𝑠)))
8786ssrdv 3574 . . . . 5 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → 𝑆 ⊆ (0...𝑠))
88 ssfi 8065 . . . . 5 (((0...𝑠) ∈ Fin ∧ 𝑆 ⊆ (0...𝑠)) → 𝑆 ∈ Fin)
8943, 87, 88sylancr 694 . . . 4 (((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) ∧ ∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)) → 𝑆 ∈ Fin)
9089ex 449 . . 3 ((𝑆 ⊆ ℕ0𝑠 ∈ ℕ0) → (∀𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) → 𝑆 ∈ Fin))
9190rexlimdva 3013 . 2 (𝑆 ⊆ ℕ0 → (∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆) → 𝑆 ∈ Fin))
9242, 91impbid 201 1 (𝑆 ⊆ ℕ0 → (𝑆 ∈ Fin ↔ ∃𝑠 ∈ ℕ0𝑥 ∈ ℕ0 (𝑠 < 𝑥𝑥𝑆)))
 Colors of variables: wff setvar class Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 195   ∨ wo 382   ∧ wa 383   ∨ w3o 1030   ∧ w3a 1031   = wceq 1475   ∈ wcel 1977   ≠ wne 2780   ∉ wnel 2781  ∀wral 2896  ∃wrex 2897   ⊆ wss 3540  ∅c0 3874   class class class wbr 4583   Or wor 4958  (class class class)co 6549  Fincfn 7841  ℝcr 9814  0cc0 9815   < clt 9953   ≤ cle 9954  ℕ0cn0 11169  ...cfz 12197 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847  ax-cnex 9871  ax-resscn 9872  ax-1cn 9873  ax-icn 9874  ax-addcl 9875  ax-addrcl 9876  ax-mulcl 9877  ax-mulrcl 9878  ax-mulcom 9879  ax-addass 9880  ax-mulass 9881  ax-distr 9882  ax-i2m1 9883  ax-1ne0 9884  ax-1rid 9885  ax-rnegex 9886  ax-rrecex 9887  ax-cnre 9888  ax-pre-lttri 9889  ax-pre-lttrn 9890  ax-pre-ltadd 9891  ax-pre-mulgt0 9892 This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-nel 2783  df-ral 2901  df-rex 2902  df-reu 2903  df-rmo 2904  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-pss 3556  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-tp 4130  df-op 4132  df-uni 4373  df-iun 4457  df-br 4584  df-opab 4644  df-mpt 4645  df-tr 4681  df-eprel 4949  df-id 4953  df-po 4959  df-so 4960  df-fr 4997  df-we 4999  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-pred 5597  df-ord 5643  df-on 5644  df-lim 5645  df-suc 5646  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-riota 6511  df-ov 6552  df-oprab 6553  df-mpt2 6554  df-om 6958  df-1st 7059  df-2nd 7060  df-wrecs 7294  df-recs 7355  df-rdg 7393  df-1o 7447  df-er 7629  df-en 7842  df-dom 7843  df-sdom 7844  df-fin 7845  df-pnf 9955  df-mnf 9956  df-xr 9957  df-ltxr 9958  df-le 9959  df-sub 10147  df-neg 10148  df-nn 10898  df-n0 11170  df-z 11255  df-uz 11564  df-fz 12198 This theorem is referenced by:  rabssnn0fi  12647
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