| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | breq1 5145 | . . . . . . . . . . . 12
⊢ (ℎ = 𝑀 → (ℎ ≤ 𝑡 ↔ 𝑀 ≤ 𝑡)) | 
| 2 | 1 | ralbidv 3177 | . . . . . . . . . . 11
⊢ (ℎ = 𝑀 → (∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 𝑀 ≤ 𝑡)) | 
| 3 | 2 | imbi2d 340 | . . . . . . . . . 10
⊢ (ℎ = 𝑀 → (((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡) ↔ ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑀 ≤ 𝑡))) | 
| 4 |  | breq1 5145 | . . . . . . . . . . . 12
⊢ (ℎ = 𝑚 → (ℎ ≤ 𝑡 ↔ 𝑚 ≤ 𝑡)) | 
| 5 | 4 | ralbidv 3177 | . . . . . . . . . . 11
⊢ (ℎ = 𝑚 → (∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡)) | 
| 6 | 5 | imbi2d 340 | . . . . . . . . . 10
⊢ (ℎ = 𝑚 → (((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡) ↔ ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡))) | 
| 7 |  | breq1 5145 | . . . . . . . . . . . 12
⊢ (ℎ = (𝑚 + 1) → (ℎ ≤ 𝑡 ↔ (𝑚 + 1) ≤ 𝑡)) | 
| 8 | 7 | ralbidv 3177 | . . . . . . . . . . 11
⊢ (ℎ = (𝑚 + 1) → (∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡)) | 
| 9 | 8 | imbi2d 340 | . . . . . . . . . 10
⊢ (ℎ = (𝑚 + 1) → (((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡) ↔ ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 10 |  | breq1 5145 | . . . . . . . . . . . 12
⊢ (ℎ = 𝑛 → (ℎ ≤ 𝑡 ↔ 𝑛 ≤ 𝑡)) | 
| 11 | 10 | ralbidv 3177 | . . . . . . . . . . 11
⊢ (ℎ = 𝑛 → (∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡)) | 
| 12 | 11 | imbi2d 340 | . . . . . . . . . 10
⊢ (ℎ = 𝑛 → (((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 ℎ ≤ 𝑡) ↔ ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡))) | 
| 13 |  | ssel 3976 | . . . . . . . . . . . . 13
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (𝑡 ∈ 𝑆 → 𝑡 ∈ (ℤ≥‘𝑀))) | 
| 14 |  | eluzle 12892 | . . . . . . . . . . . . 13
⊢ (𝑡 ∈
(ℤ≥‘𝑀) → 𝑀 ≤ 𝑡) | 
| 15 | 13, 14 | syl6 35 | . . . . . . . . . . . 12
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (𝑡 ∈ 𝑆 → 𝑀 ≤ 𝑡)) | 
| 16 | 15 | ralrimiv 3144 | . . . . . . . . . . 11
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → ∀𝑡 ∈ 𝑆 𝑀 ≤ 𝑡) | 
| 17 | 16 | adantr 480 | . . . . . . . . . 10
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑀 ≤ 𝑡) | 
| 18 |  | uzssz 12900 | . . . . . . . . . . . . 13
⊢
(ℤ≥‘𝑀) ⊆ ℤ | 
| 19 |  | sstr 3991 | . . . . . . . . . . . . 13
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ (ℤ≥‘𝑀) ⊆ ℤ) → 𝑆 ⊆
ℤ) | 
| 20 | 18, 19 | mpan2 691 | . . . . . . . . . . . 12
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → 𝑆 ⊆ ℤ) | 
| 21 |  | eluzelz 12889 | . . . . . . . . . . . . 13
⊢ (𝑚 ∈
(ℤ≥‘𝑀) → 𝑚 ∈ ℤ) | 
| 22 |  | breq1 5145 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑗 = 𝑚 → (𝑗 ≤ 𝑡 ↔ 𝑚 ≤ 𝑡)) | 
| 23 | 22 | ralbidv 3177 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑗 = 𝑚 → (∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡)) | 
| 24 | 23 | rspcev 3621 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝑚 ∈ 𝑆 ∧ ∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡) → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) | 
| 25 | 24 | expcom 413 | . . . . . . . . . . . . . . . . 17
⊢
(∀𝑡 ∈
𝑆 𝑚 ≤ 𝑡 → (𝑚 ∈ 𝑆 → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡)) | 
| 26 | 25 | con3rr3 155 | . . . . . . . . . . . . . . . 16
⊢ (¬
∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ¬ 𝑚 ∈ 𝑆)) | 
| 27 |  | ssel2 3977 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆) → 𝑡 ∈ ℤ) | 
| 28 |  | zre 12619 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝑚 ∈ ℤ → 𝑚 ∈
ℝ) | 
| 29 |  | zre 12619 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝑡 ∈ ℤ → 𝑡 ∈
ℝ) | 
| 30 |  | letri3 11347 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑚 ∈ ℝ ∧ 𝑡 ∈ ℝ) → (𝑚 = 𝑡 ↔ (𝑚 ≤ 𝑡 ∧ 𝑡 ≤ 𝑚))) | 
| 31 | 28, 29, 30 | syl2an 596 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑚 ∈ ℤ ∧ 𝑡 ∈ ℤ) → (𝑚 = 𝑡 ↔ (𝑚 ≤ 𝑡 ∧ 𝑡 ≤ 𝑚))) | 
| 32 |  | zleltp1 12670 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑡 ∈ ℤ ∧ 𝑚 ∈ ℤ) → (𝑡 ≤ 𝑚 ↔ 𝑡 < (𝑚 + 1))) | 
| 33 |  | peano2re 11435 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ (𝑚 ∈ ℝ → (𝑚 + 1) ∈
ℝ) | 
| 34 | 28, 33 | syl 17 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (𝑚 ∈ ℤ → (𝑚 + 1) ∈
ℝ) | 
| 35 |  | ltnle 11341 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑡 ∈ ℝ ∧ (𝑚 + 1) ∈ ℝ) →
(𝑡 < (𝑚 + 1) ↔ ¬ (𝑚 + 1) ≤ 𝑡)) | 
| 36 | 29, 34, 35 | syl2an 596 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑡 ∈ ℤ ∧ 𝑚 ∈ ℤ) → (𝑡 < (𝑚 + 1) ↔ ¬ (𝑚 + 1) ≤ 𝑡)) | 
| 37 | 32, 36 | bitrd 279 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑡 ∈ ℤ ∧ 𝑚 ∈ ℤ) → (𝑡 ≤ 𝑚 ↔ ¬ (𝑚 + 1) ≤ 𝑡)) | 
| 38 | 37 | ancoms 458 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑚 ∈ ℤ ∧ 𝑡 ∈ ℤ) → (𝑡 ≤ 𝑚 ↔ ¬ (𝑚 + 1) ≤ 𝑡)) | 
| 39 | 38 | anbi2d 630 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑚 ∈ ℤ ∧ 𝑡 ∈ ℤ) → ((𝑚 ≤ 𝑡 ∧ 𝑡 ≤ 𝑚) ↔ (𝑚 ≤ 𝑡 ∧ ¬ (𝑚 + 1) ≤ 𝑡))) | 
| 40 | 31, 39 | bitrd 279 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑚 ∈ ℤ ∧ 𝑡 ∈ ℤ) → (𝑚 = 𝑡 ↔ (𝑚 ≤ 𝑡 ∧ ¬ (𝑚 + 1) ≤ 𝑡))) | 
| 41 | 27, 40 | sylan2 593 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → (𝑚 = 𝑡 ↔ (𝑚 ≤ 𝑡 ∧ ¬ (𝑚 + 1) ≤ 𝑡))) | 
| 42 |  | eleq1a 2835 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ (𝑡 ∈ 𝑆 → (𝑚 = 𝑡 → 𝑚 ∈ 𝑆)) | 
| 43 | 42 | ad2antll 729 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → (𝑚 = 𝑡 → 𝑚 ∈ 𝑆)) | 
| 44 | 41, 43 | sylbird 260 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → ((𝑚 ≤ 𝑡 ∧ ¬ (𝑚 + 1) ≤ 𝑡) → 𝑚 ∈ 𝑆)) | 
| 45 | 44 | expd 415 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → (𝑚 ≤ 𝑡 → (¬ (𝑚 + 1) ≤ 𝑡 → 𝑚 ∈ 𝑆))) | 
| 46 |  | con1 146 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ ((¬
(𝑚 + 1) ≤ 𝑡 → 𝑚 ∈ 𝑆) → (¬ 𝑚 ∈ 𝑆 → (𝑚 + 1) ≤ 𝑡)) | 
| 47 | 45, 46 | syl6 35 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → (𝑚 ≤ 𝑡 → (¬ 𝑚 ∈ 𝑆 → (𝑚 + 1) ≤ 𝑡))) | 
| 48 | 47 | com23 86 | . . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝑚 ∈ ℤ ∧ (𝑆 ⊆ ℤ ∧ 𝑡 ∈ 𝑆)) → (¬ 𝑚 ∈ 𝑆 → (𝑚 ≤ 𝑡 → (𝑚 + 1) ≤ 𝑡))) | 
| 49 | 48 | exp32 420 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑚 ∈ ℤ → (𝑆 ⊆ ℤ → (𝑡 ∈ 𝑆 → (¬ 𝑚 ∈ 𝑆 → (𝑚 ≤ 𝑡 → (𝑚 + 1) ≤ 𝑡))))) | 
| 50 | 49 | com34 91 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑚 ∈ ℤ → (𝑆 ⊆ ℤ → (¬
𝑚 ∈ 𝑆 → (𝑡 ∈ 𝑆 → (𝑚 ≤ 𝑡 → (𝑚 + 1) ≤ 𝑡))))) | 
| 51 | 50 | imp41 425 | . . . . . . . . . . . . . . . . . 18
⊢ ((((𝑚 ∈ ℤ ∧ 𝑆 ⊆ ℤ) ∧ ¬
𝑚 ∈ 𝑆) ∧ 𝑡 ∈ 𝑆) → (𝑚 ≤ 𝑡 → (𝑚 + 1) ≤ 𝑡)) | 
| 52 | 51 | ralimdva 3166 | . . . . . . . . . . . . . . . . 17
⊢ (((𝑚 ∈ ℤ ∧ 𝑆 ⊆ ℤ) ∧ ¬
𝑚 ∈ 𝑆) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡)) | 
| 53 | 52 | ex 412 | . . . . . . . . . . . . . . . 16
⊢ ((𝑚 ∈ ℤ ∧ 𝑆 ⊆ ℤ) → (¬
𝑚 ∈ 𝑆 → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 54 | 26, 53 | sylan9r 508 | . . . . . . . . . . . . . . 15
⊢ (((𝑚 ∈ ℤ ∧ 𝑆 ⊆ ℤ) ∧ ¬
∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 55 | 54 | pm2.43d 53 | . . . . . . . . . . . . . 14
⊢ (((𝑚 ∈ ℤ ∧ 𝑆 ⊆ ℤ) ∧ ¬
∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡)) | 
| 56 | 55 | expl 457 | . . . . . . . . . . . . 13
⊢ (𝑚 ∈ ℤ → ((𝑆 ⊆ ℤ ∧ ¬
∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 57 | 21, 56 | syl 17 | . . . . . . . . . . . 12
⊢ (𝑚 ∈
(ℤ≥‘𝑀) → ((𝑆 ⊆ ℤ ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 58 | 20, 57 | sylani 604 | . . . . . . . . . . 11
⊢ (𝑚 ∈
(ℤ≥‘𝑀) → ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡 → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 59 | 58 | a2d 29 | . . . . . . . . . 10
⊢ (𝑚 ∈
(ℤ≥‘𝑀) → (((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑚 ≤ 𝑡) → ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 (𝑚 + 1) ≤ 𝑡))) | 
| 60 | 3, 6, 9, 12, 17, 59 | uzind4i 12953 | . . . . . . . . 9
⊢ (𝑛 ∈
(ℤ≥‘𝑀) → ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡)) | 
| 61 |  | breq1 5145 | . . . . . . . . . . . . . 14
⊢ (𝑗 = 𝑛 → (𝑗 ≤ 𝑡 ↔ 𝑛 ≤ 𝑡)) | 
| 62 | 61 | ralbidv 3177 | . . . . . . . . . . . . 13
⊢ (𝑗 = 𝑛 → (∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 ↔ ∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡)) | 
| 63 | 62 | rspcev 3621 | . . . . . . . . . . . 12
⊢ ((𝑛 ∈ 𝑆 ∧ ∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡) → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) | 
| 64 | 63 | expcom 413 | . . . . . . . . . . 11
⊢
(∀𝑡 ∈
𝑆 𝑛 ≤ 𝑡 → (𝑛 ∈ 𝑆 → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡)) | 
| 65 | 64 | con3rr3 155 | . . . . . . . . . 10
⊢ (¬
∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 → (∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡 → ¬ 𝑛 ∈ 𝑆)) | 
| 66 | 65 | adantl 481 | . . . . . . . . 9
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → (∀𝑡 ∈ 𝑆 𝑛 ≤ 𝑡 → ¬ 𝑛 ∈ 𝑆)) | 
| 67 | 60, 66 | sylcom 30 | . . . . . . . 8
⊢ (𝑛 ∈
(ℤ≥‘𝑀) → ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ¬ 𝑛 ∈ 𝑆)) | 
| 68 |  | ssel 3976 | . . . . . . . . . 10
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (𝑛 ∈ 𝑆 → 𝑛 ∈ (ℤ≥‘𝑀))) | 
| 69 | 68 | con3rr3 155 | . . . . . . . . 9
⊢ (¬
𝑛 ∈
(ℤ≥‘𝑀) → (𝑆 ⊆ (ℤ≥‘𝑀) → ¬ 𝑛 ∈ 𝑆)) | 
| 70 | 69 | adantrd 491 | . . . . . . . 8
⊢ (¬
𝑛 ∈
(ℤ≥‘𝑀) → ((𝑆 ⊆ (ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ¬ 𝑛 ∈ 𝑆)) | 
| 71 | 67, 70 | pm2.61i 182 | . . . . . . 7
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ ¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) → ¬ 𝑛 ∈ 𝑆) | 
| 72 | 71 | ex 412 | . . . . . 6
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 → ¬ 𝑛 ∈ 𝑆)) | 
| 73 | 72 | alrimdv 1928 | . . . . 5
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 → ∀𝑛 ¬ 𝑛 ∈ 𝑆)) | 
| 74 |  | eq0 4349 | . . . . 5
⊢ (𝑆 = ∅ ↔ ∀𝑛 ¬ 𝑛 ∈ 𝑆) | 
| 75 | 73, 74 | imbitrrdi 252 | . . . 4
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (¬ ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 → 𝑆 = ∅)) | 
| 76 | 75 | necon1ad 2956 | . . 3
⊢ (𝑆 ⊆
(ℤ≥‘𝑀) → (𝑆 ≠ ∅ → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡)) | 
| 77 | 76 | imp 406 | . 2
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ 𝑆 ≠ ∅) → ∃𝑗 ∈ 𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡) | 
| 78 |  | breq2 5146 | . . . 4
⊢ (𝑡 = 𝑘 → (𝑗 ≤ 𝑡 ↔ 𝑗 ≤ 𝑘)) | 
| 79 | 78 | cbvralvw 3236 | . . 3
⊢
(∀𝑡 ∈
𝑆 𝑗 ≤ 𝑡 ↔ ∀𝑘 ∈ 𝑆 𝑗 ≤ 𝑘) | 
| 80 | 79 | rexbii 3093 | . 2
⊢
(∃𝑗 ∈
𝑆 ∀𝑡 ∈ 𝑆 𝑗 ≤ 𝑡 ↔ ∃𝑗 ∈ 𝑆 ∀𝑘 ∈ 𝑆 𝑗 ≤ 𝑘) | 
| 81 | 77, 80 | sylib 218 | 1
⊢ ((𝑆 ⊆
(ℤ≥‘𝑀) ∧ 𝑆 ≠ ∅) → ∃𝑗 ∈ 𝑆 ∀𝑘 ∈ 𝑆 𝑗 ≤ 𝑘) |