| Step | Hyp | Ref
 | Expression | 
| 1 |   | exbtwnzlemshrink.j | 
. . 3
⊢ (𝜑 → 𝐽 ∈ ℕ) | 
| 2 | 1 | adantr 276 | 
. 2
⊢ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽))) → 𝐽 ∈ ℕ) | 
| 3 |   | oveq2 5930 | 
. . . . . . . 8
⊢ (𝑤 = 1 → (𝑚 + 𝑤) = (𝑚 + 1)) | 
| 4 | 3 | breq2d 4045 | 
. . . . . . 7
⊢ (𝑤 = 1 → (𝐴 < (𝑚 + 𝑤) ↔ 𝐴 < (𝑚 + 1))) | 
| 5 | 4 | anbi2d 464 | 
. . . . . 6
⊢ (𝑤 = 1 → ((𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1)))) | 
| 6 | 5 | rexbidv 2498 | 
. . . . 5
⊢ (𝑤 = 1 → (∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1)))) | 
| 7 | 6 | anbi2d 464 | 
. . . 4
⊢ (𝑤 = 1 → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) ↔ (𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1))))) | 
| 8 | 7 | imbi1d 231 | 
. . 3
⊢ (𝑤 = 1 → (((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) ↔ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))))) | 
| 9 |   | oveq2 5930 | 
. . . . . . . 8
⊢ (𝑤 = 𝑘 → (𝑚 + 𝑤) = (𝑚 + 𝑘)) | 
| 10 | 9 | breq2d 4045 | 
. . . . . . 7
⊢ (𝑤 = 𝑘 → (𝐴 < (𝑚 + 𝑤) ↔ 𝐴 < (𝑚 + 𝑘))) | 
| 11 | 10 | anbi2d 464 | 
. . . . . 6
⊢ (𝑤 = 𝑘 → ((𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘)))) | 
| 12 | 11 | rexbidv 2498 | 
. . . . 5
⊢ (𝑤 = 𝑘 → (∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘)))) | 
| 13 | 12 | anbi2d 464 | 
. . . 4
⊢ (𝑤 = 𝑘 → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) ↔ (𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘))))) | 
| 14 | 13 | imbi1d 231 | 
. . 3
⊢ (𝑤 = 𝑘 → (((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) ↔ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))))) | 
| 15 |   | oveq2 5930 | 
. . . . . . . 8
⊢ (𝑤 = (𝑘 + 1) → (𝑚 + 𝑤) = (𝑚 + (𝑘 + 1))) | 
| 16 | 15 | breq2d 4045 | 
. . . . . . 7
⊢ (𝑤 = (𝑘 + 1) → (𝐴 < (𝑚 + 𝑤) ↔ 𝐴 < (𝑚 + (𝑘 + 1)))) | 
| 17 | 16 | anbi2d 464 | 
. . . . . 6
⊢ (𝑤 = (𝑘 + 1) → ((𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1))))) | 
| 18 | 17 | rexbidv 2498 | 
. . . . 5
⊢ (𝑤 = (𝑘 + 1) → (∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1))))) | 
| 19 | 18 | anbi2d 464 | 
. . . 4
⊢ (𝑤 = (𝑘 + 1) → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) ↔ (𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1)))))) | 
| 20 | 19 | imbi1d 231 | 
. . 3
⊢ (𝑤 = (𝑘 + 1) → (((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) ↔ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1)))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))))) | 
| 21 |   | oveq2 5930 | 
. . . . . . . 8
⊢ (𝑤 = 𝐽 → (𝑚 + 𝑤) = (𝑚 + 𝐽)) | 
| 22 | 21 | breq2d 4045 | 
. . . . . . 7
⊢ (𝑤 = 𝐽 → (𝐴 < (𝑚 + 𝑤) ↔ 𝐴 < (𝑚 + 𝐽))) | 
| 23 | 22 | anbi2d 464 | 
. . . . . 6
⊢ (𝑤 = 𝐽 → ((𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽)))) | 
| 24 | 23 | rexbidv 2498 | 
. . . . 5
⊢ (𝑤 = 𝐽 → (∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤)) ↔ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽)))) | 
| 25 | 24 | anbi2d 464 | 
. . . 4
⊢ (𝑤 = 𝐽 → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) ↔ (𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽))))) | 
| 26 | 25 | imbi1d 231 | 
. . 3
⊢ (𝑤 = 𝐽 → (((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑤))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) ↔ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))))) | 
| 27 |   | breq1 4036 | 
. . . . . . 7
⊢ (𝑚 = 𝑥 → (𝑚 ≤ 𝐴 ↔ 𝑥 ≤ 𝐴)) | 
| 28 |   | oveq1 5929 | 
. . . . . . . 8
⊢ (𝑚 = 𝑥 → (𝑚 + 1) = (𝑥 + 1)) | 
| 29 | 28 | breq2d 4045 | 
. . . . . . 7
⊢ (𝑚 = 𝑥 → (𝐴 < (𝑚 + 1) ↔ 𝐴 < (𝑥 + 1))) | 
| 30 | 27, 29 | anbi12d 473 | 
. . . . . 6
⊢ (𝑚 = 𝑥 → ((𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1)) ↔ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1)))) | 
| 31 | 30 | cbvrexv 2730 | 
. . . . 5
⊢
(∃𝑚 ∈
ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1)) ↔ ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) | 
| 32 | 31 | biimpi 120 | 
. . . 4
⊢
(∃𝑚 ∈
ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1)) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) | 
| 33 | 32 | adantl 277 | 
. . 3
⊢ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 1))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) | 
| 34 |   | simpl 109 | 
. . . . . . 7
⊢ ((𝑘 ∈ ℕ ∧ 𝜑) → 𝑘 ∈ ℕ) | 
| 35 |   | exbtwnzlemshrink.a | 
. . . . . . . 8
⊢ (𝜑 → 𝐴 ∈ ℝ) | 
| 36 | 35 | adantl 277 | 
. . . . . . 7
⊢ ((𝑘 ∈ ℕ ∧ 𝜑) → 𝐴 ∈ ℝ) | 
| 37 |   | exbtwnzlemshrink.tri | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑛 ∈ ℤ) → (𝑛 ≤ 𝐴 ∨ 𝐴 < 𝑛)) | 
| 38 | 37 | adantll 476 | 
. . . . . . 7
⊢ (((𝑘 ∈ ℕ ∧ 𝜑) ∧ 𝑛 ∈ ℤ) → (𝑛 ≤ 𝐴 ∨ 𝐴 < 𝑛)) | 
| 39 | 34, 36, 38 | exbtwnzlemstep 10337 | 
. . . . . 6
⊢ (((𝑘 ∈ ℕ ∧ 𝜑) ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1)))) → ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘))) | 
| 40 | 39 | ex 115 | 
. . . . 5
⊢ ((𝑘 ∈ ℕ ∧ 𝜑) → (∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1))) → ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘)))) | 
| 41 | 40 | imdistanda 448 | 
. . . 4
⊢ (𝑘 ∈ ℕ → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1)))) → (𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘))))) | 
| 42 | 41 | imim1d 75 | 
. . 3
⊢ (𝑘 ∈ ℕ → (((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝑘))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + (𝑘 + 1)))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))))) | 
| 43 | 8, 14, 20, 26, 33, 42 | nnind 9006 | 
. 2
⊢ (𝐽 ∈ ℕ → ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1)))) | 
| 44 | 2, 43 | mpcom 36 | 
1
⊢ ((𝜑 ∧ ∃𝑚 ∈ ℤ (𝑚 ≤ 𝐴 ∧ 𝐴 < (𝑚 + 𝐽))) → ∃𝑥 ∈ ℤ (𝑥 ≤ 𝐴 ∧ 𝐴 < (𝑥 + 1))) |