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Theorem sqr2irr 12768
Description: The square root of 2 is irrational. See zsqrelqelz 13070 for a generalization to all non-square integers. The proof's core is proven in sqr2irrlem 12767, which shows that if 𝐴 / 𝐵 = √(2), then 𝐴 and 𝐵 are even, so 𝐴 / 2 and 𝐵 / 2 are smaller representatives, which is absurd. An older version of this proof was included in The Seventeen Provers of the World compiled by Freek Wiedijk. It is also the first "top 100" mathematical theorems whose formalization is tracked by Freek Wiedijk on his Formalizing 100 Theorems page at http://www.cs.ru.nl/~freek/100/. (Contributed by NM, 8-Jan-2002.) (Proof shortened by Mario Carneiro, 12-Sep-2015.)
Assertion
Ref Expression
sqr2irr (√‘2) ∉ ℚ

Proof of Theorem sqr2irr
Dummy variables 𝑥 𝑛 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 peano2nn 9937 . . . . . 6 (𝑦 ∈ ℕ → (𝑦 + 1) ∈ ℕ)
2 breq2 4150 . . . . . . . . 9 (𝑛 = 1 → (𝑧 < 𝑛𝑧 < 1))
32imbi1d 309 . . . . . . . 8 (𝑛 = 1 → ((𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ (𝑧 < 1 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
43ralbidv 2662 . . . . . . 7 (𝑛 = 1 → (∀𝑧 ∈ ℕ (𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ∀𝑧 ∈ ℕ (𝑧 < 1 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
5 breq2 4150 . . . . . . . . 9 (𝑛 = 𝑦 → (𝑧 < 𝑛𝑧 < 𝑦))
65imbi1d 309 . . . . . . . 8 (𝑛 = 𝑦 → ((𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
76ralbidv 2662 . . . . . . 7 (𝑛 = 𝑦 → (∀𝑧 ∈ ℕ (𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
8 breq2 4150 . . . . . . . . 9 (𝑛 = (𝑦 + 1) → (𝑧 < 𝑛𝑧 < (𝑦 + 1)))
98imbi1d 309 . . . . . . . 8 (𝑛 = (𝑦 + 1) → ((𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
109ralbidv 2662 . . . . . . 7 (𝑛 = (𝑦 + 1) → (∀𝑧 ∈ ℕ (𝑧 < 𝑛 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
11 nnnlt1 9955 . . . . . . . . 9 (𝑧 ∈ ℕ → ¬ 𝑧 < 1)
1211pm2.21d 100 . . . . . . . 8 (𝑧 ∈ ℕ → (𝑧 < 1 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))
1312rgen 2707 . . . . . . 7 𝑧 ∈ ℕ (𝑧 < 1 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))
14 nnrp 10546 . . . . . . . . . . . . . 14 (𝑦 ∈ ℕ → 𝑦 ∈ ℝ+)
15 rphalflt 10563 . . . . . . . . . . . . . 14 (𝑦 ∈ ℝ+ → (𝑦 / 2) < 𝑦)
1614, 15syl 16 . . . . . . . . . . . . 13 (𝑦 ∈ ℕ → (𝑦 / 2) < 𝑦)
17 breq1 4149 . . . . . . . . . . . . . . . 16 (𝑧 = (𝑦 / 2) → (𝑧 < 𝑦 ↔ (𝑦 / 2) < 𝑦))
18 oveq2 6021 . . . . . . . . . . . . . . . . . 18 (𝑧 = (𝑦 / 2) → (𝑥 / 𝑧) = (𝑥 / (𝑦 / 2)))
1918neeq2d 2557 . . . . . . . . . . . . . . . . 17 (𝑧 = (𝑦 / 2) → ((√‘2) ≠ (𝑥 / 𝑧) ↔ (√‘2) ≠ (𝑥 / (𝑦 / 2))))
2019ralbidv 2662 . . . . . . . . . . . . . . . 16 (𝑧 = (𝑦 / 2) → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧) ↔ ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2))))
2117, 20imbi12d 312 . . . . . . . . . . . . . . 15 (𝑧 = (𝑦 / 2) → ((𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ((𝑦 / 2) < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
2221rspcv 2984 . . . . . . . . . . . . . 14 ((𝑦 / 2) ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ((𝑦 / 2) < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
2322com13 76 . . . . . . . . . . . . 13 ((𝑦 / 2) < 𝑦 → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
2416, 23syl 16 . . . . . . . . . . . 12 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
25 simpr 448 . . . . . . . . . . . . . . . . 17 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (√‘2) = (𝑧 / 𝑦))
26 zcn 10212 . . . . . . . . . . . . . . . . . . 19 (𝑧 ∈ ℤ → 𝑧 ∈ ℂ)
2726ad2antlr 708 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 𝑧 ∈ ℂ)
28 nncn 9933 . . . . . . . . . . . . . . . . . . 19 (𝑦 ∈ ℕ → 𝑦 ∈ ℂ)
2928ad2antrr 707 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 𝑦 ∈ ℂ)
30 2cn 9995 . . . . . . . . . . . . . . . . . . 19 2 ∈ ℂ
3130a1i 11 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 2 ∈ ℂ)
32 nnne0 9957 . . . . . . . . . . . . . . . . . . 19 (𝑦 ∈ ℕ → 𝑦 ≠ 0)
3332ad2antrr 707 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 𝑦 ≠ 0)
34 2ne0 10008 . . . . . . . . . . . . . . . . . . 19 2 ≠ 0
3534a1i 11 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 2 ≠ 0)
3627, 29, 31, 33, 35divcan7d 9743 . . . . . . . . . . . . . . . . 17 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → ((𝑧 / 2) / (𝑦 / 2)) = (𝑧 / 𝑦))
3725, 36eqtr4d 2415 . . . . . . . . . . . . . . . 16 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (√‘2) = ((𝑧 / 2) / (𝑦 / 2)))
38 simplr 732 . . . . . . . . . . . . . . . . . . . 20 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 𝑧 ∈ ℤ)
39 simpll 731 . . . . . . . . . . . . . . . . . . . 20 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → 𝑦 ∈ ℕ)
4038, 39, 25sqr2irrlem 12767 . . . . . . . . . . . . . . . . . . 19 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → ((𝑧 / 2) ∈ ℤ ∧ (𝑦 / 2) ∈ ℕ))
4140simprd 450 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (𝑦 / 2) ∈ ℕ)
4240simpld 446 . . . . . . . . . . . . . . . . . . 19 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (𝑧 / 2) ∈ ℤ)
43 oveq1 6020 . . . . . . . . . . . . . . . . . . . . 21 (𝑥 = (𝑧 / 2) → (𝑥 / (𝑦 / 2)) = ((𝑧 / 2) / (𝑦 / 2)))
4443neeq2d 2557 . . . . . . . . . . . . . . . . . . . 20 (𝑥 = (𝑧 / 2) → ((√‘2) ≠ (𝑥 / (𝑦 / 2)) ↔ (√‘2) ≠ ((𝑧 / 2) / (𝑦 / 2))))
4544rspcv 2984 . . . . . . . . . . . . . . . . . . 19 ((𝑧 / 2) ∈ ℤ → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)) → (√‘2) ≠ ((𝑧 / 2) / (𝑦 / 2))))
4642, 45syl 16 . . . . . . . . . . . . . . . . . 18 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)) → (√‘2) ≠ ((𝑧 / 2) / (𝑦 / 2))))
4741, 46embantd 52 . . . . . . . . . . . . . . . . 17 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → (((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2))) → (√‘2) ≠ ((𝑧 / 2) / (𝑦 / 2))))
4847necon2bd 2592 . . . . . . . . . . . . . . . 16 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → ((√‘2) = ((𝑧 / 2) / (𝑦 / 2)) → ¬ ((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
4937, 48mpd 15 . . . . . . . . . . . . . . 15 (((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) ∧ (√‘2) = (𝑧 / 𝑦)) → ¬ ((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2))))
5049ex 424 . . . . . . . . . . . . . 14 ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) → ((√‘2) = (𝑧 / 𝑦) → ¬ ((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2)))))
5150necon2ad 2591 . . . . . . . . . . . . 13 ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) → (((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2))) → (√‘2) ≠ (𝑧 / 𝑦)))
5251ralrimdva 2732 . . . . . . . . . . . 12 (𝑦 ∈ ℕ → (((𝑦 / 2) ∈ ℕ → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / (𝑦 / 2))) → ∀𝑧 ∈ ℤ (√‘2) ≠ (𝑧 / 𝑦)))
5324, 52syld 42 . . . . . . . . . . 11 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ∀𝑧 ∈ ℤ (√‘2) ≠ (𝑧 / 𝑦)))
54 oveq1 6020 . . . . . . . . . . . . 13 (𝑥 = 𝑧 → (𝑥 / 𝑦) = (𝑧 / 𝑦))
5554neeq2d 2557 . . . . . . . . . . . 12 (𝑥 = 𝑧 → ((√‘2) ≠ (𝑥 / 𝑦) ↔ (√‘2) ≠ (𝑧 / 𝑦)))
5655cbvralv 2868 . . . . . . . . . . 11 (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑦) ↔ ∀𝑧 ∈ ℤ (√‘2) ≠ (𝑧 / 𝑦))
5753, 56syl6ibr 219 . . . . . . . . . 10 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑦)))
58 oveq2 6021 . . . . . . . . . . . . 13 (𝑧 = 𝑦 → (𝑥 / 𝑧) = (𝑥 / 𝑦))
5958neeq2d 2557 . . . . . . . . . . . 12 (𝑧 = 𝑦 → ((√‘2) ≠ (𝑥 / 𝑧) ↔ (√‘2) ≠ (𝑥 / 𝑦)))
6059ralbidv 2662 . . . . . . . . . . 11 (𝑧 = 𝑦 → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧) ↔ ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑦)))
6160ceqsralv 2919 . . . . . . . . . 10 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑦)))
6257, 61sylibrd 226 . . . . . . . . 9 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ∀𝑧 ∈ ℕ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
6362ancld 537 . . . . . . . 8 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ ∀𝑧 ∈ ℕ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))))
64 nnleltp1 10254 . . . . . . . . . . . . . 14 ((𝑧 ∈ ℕ ∧ 𝑦 ∈ ℕ) → (𝑧𝑦𝑧 < (𝑦 + 1)))
65 nnre 9932 . . . . . . . . . . . . . . 15 (𝑧 ∈ ℕ → 𝑧 ∈ ℝ)
66 nnre 9932 . . . . . . . . . . . . . . 15 (𝑦 ∈ ℕ → 𝑦 ∈ ℝ)
67 leloe 9087 . . . . . . . . . . . . . . 15 ((𝑧 ∈ ℝ ∧ 𝑦 ∈ ℝ) → (𝑧𝑦 ↔ (𝑧 < 𝑦𝑧 = 𝑦)))
6865, 66, 67syl2an 464 . . . . . . . . . . . . . 14 ((𝑧 ∈ ℕ ∧ 𝑦 ∈ ℕ) → (𝑧𝑦 ↔ (𝑧 < 𝑦𝑧 = 𝑦)))
6964, 68bitr3d 247 . . . . . . . . . . . . 13 ((𝑧 ∈ ℕ ∧ 𝑦 ∈ ℕ) → (𝑧 < (𝑦 + 1) ↔ (𝑧 < 𝑦𝑧 = 𝑦)))
7069ancoms 440 . . . . . . . . . . . 12 ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℕ) → (𝑧 < (𝑦 + 1) ↔ (𝑧 < 𝑦𝑧 = 𝑦)))
7170imbi1d 309 . . . . . . . . . . 11 ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℕ) → ((𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ((𝑧 < 𝑦𝑧 = 𝑦) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
72 jaob 759 . . . . . . . . . . 11 (((𝑧 < 𝑦𝑧 = 𝑦) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ((𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
7371, 72syl6bb 253 . . . . . . . . . 10 ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℕ) → ((𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ((𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))))
7473ralbidva 2658 . . . . . . . . 9 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ ∀𝑧 ∈ ℕ ((𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))))
75 r19.26 2774 . . . . . . . . 9 (∀𝑧 ∈ ℕ ((𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))) ↔ (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ ∀𝑧 ∈ ℕ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
7674, 75syl6bb 253 . . . . . . . 8 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ∧ ∀𝑧 ∈ ℕ (𝑧 = 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))))
7763, 76sylibrd 226 . . . . . . 7 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < 𝑦 → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → ∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧))))
784, 7, 10, 10, 13, 77nnind 9943 . . . . . 6 ((𝑦 + 1) ∈ ℕ → ∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))
791, 78syl 16 . . . . 5 (𝑦 ∈ ℕ → ∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)))
8066ltp1d 9866 . . . . 5 (𝑦 ∈ ℕ → 𝑦 < (𝑦 + 1))
81 breq1 4149 . . . . . . 7 (𝑧 = 𝑦 → (𝑧 < (𝑦 + 1) ↔ 𝑦 < (𝑦 + 1)))
82 df-ne 2545 . . . . . . . . . 10 ((√‘2) ≠ (𝑥 / 𝑦) ↔ ¬ (√‘2) = (𝑥 / 𝑦))
8359, 82syl6bb 253 . . . . . . . . 9 (𝑧 = 𝑦 → ((√‘2) ≠ (𝑥 / 𝑧) ↔ ¬ (√‘2) = (𝑥 / 𝑦)))
8483ralbidv 2662 . . . . . . . 8 (𝑧 = 𝑦 → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧) ↔ ∀𝑥 ∈ ℤ ¬ (√‘2) = (𝑥 / 𝑦)))
85 ralnex 2652 . . . . . . . 8 (∀𝑥 ∈ ℤ ¬ (√‘2) = (𝑥 / 𝑦) ↔ ¬ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))
8684, 85syl6bb 253 . . . . . . 7 (𝑧 = 𝑦 → (∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧) ↔ ¬ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦)))
8781, 86imbi12d 312 . . . . . 6 (𝑧 = 𝑦 → ((𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) ↔ (𝑦 < (𝑦 + 1) → ¬ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))))
8887rspcv 2984 . . . . 5 (𝑦 ∈ ℕ → (∀𝑧 ∈ ℕ (𝑧 < (𝑦 + 1) → ∀𝑥 ∈ ℤ (√‘2) ≠ (𝑥 / 𝑧)) → (𝑦 < (𝑦 + 1) → ¬ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))))
8979, 80, 88mp2d 43 . . . 4 (𝑦 ∈ ℕ → ¬ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))
9089nrex 2744 . . 3 ¬ ∃𝑦 ∈ ℕ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦)
91 elq 10501 . . . 4 ((√‘2) ∈ ℚ ↔ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℕ (√‘2) = (𝑥 / 𝑦))
92 rexcom 2805 . . . 4 (∃𝑥 ∈ ℤ ∃𝑦 ∈ ℕ (√‘2) = (𝑥 / 𝑦) ↔ ∃𝑦 ∈ ℕ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))
9391, 92bitri 241 . . 3 ((√‘2) ∈ ℚ ↔ ∃𝑦 ∈ ℕ ∃𝑥 ∈ ℤ (√‘2) = (𝑥 / 𝑦))
9490, 93mtbir 291 . 2 ¬ (√‘2) ∈ ℚ
95 df-nel 2546 . 2 ((√‘2) ∉ ℚ ↔ ¬ (√‘2) ∈ ℚ)
9694, 95mpbir 201 1 (√‘2) ∉ ℚ
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wb 177  wo 358  wa 359   = wceq 1649  wcel 1717  wne 2543  wnel 2544  wral 2642  wrex 2643   class class class wbr 4146  cfv 5387  (class class class)co 6013  cc 8914  cr 8915  0cc0 8916  1c1 8917   + caddc 8919   < clt 9046  cle 9047   / cdiv 9602  cn 9925  2c2 9974  cz 10207  cq 10499  +crp 10537  csqr 11958
This theorem is referenced by:  nthruc  12770
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1552  ax-5 1563  ax-17 1623  ax-9 1661  ax-8 1682  ax-13 1719  ax-14 1721  ax-6 1736  ax-7 1741  ax-11 1753  ax-12 1939  ax-ext 2361  ax-sep 4264  ax-nul 4272  ax-pow 4311  ax-pr 4337  ax-un 4634  ax-cnex 8972  ax-resscn 8973  ax-1cn 8974  ax-icn 8975  ax-addcl 8976  ax-addrcl 8977  ax-mulcl 8978  ax-mulrcl 8979  ax-mulcom 8980  ax-addass 8981  ax-mulass 8982  ax-distr 8983  ax-i2m1 8984  ax-1ne0 8985  ax-1rid 8986  ax-rnegex 8987  ax-rrecex 8988  ax-cnre 8989  ax-pre-lttri 8990  ax-pre-lttrn 8991  ax-pre-ltadd 8992  ax-pre-mulgt0 8993  ax-pre-sup 8994
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3or 937  df-3an 938  df-tru 1325  df-ex 1548  df-nf 1551  df-sb 1656  df-eu 2235  df-mo 2236  df-clab 2367  df-cleq 2373  df-clel 2376  df-nfc 2505  df-ne 2545  df-nel 2546  df-ral 2647  df-rex 2648  df-reu 2649  df-rmo 2650  df-rab 2651  df-v 2894  df-sbc 3098  df-csb 3188  df-dif 3259  df-un 3261  df-in 3263  df-ss 3270  df-pss 3272  df-nul 3565  df-if 3676  df-pw 3737  df-sn 3756  df-pr 3757  df-tp 3758  df-op 3759  df-uni 3951  df-iun 4030  df-br 4147  df-opab 4201  df-mpt 4202  df-tr 4237  df-eprel 4428  df-id 4432  df-po 4437  df-so 4438  df-fr 4475  df-we 4477  df-ord 4518  df-on 4519  df-lim 4520  df-suc 4521  df-om 4779  df-xp 4817  df-rel 4818  df-cnv 4819  df-co 4820  df-dm 4821  df-rn 4822  df-res 4823  df-ima 4824  df-iota 5351  df-fun 5389  df-fn 5390  df-f 5391  df-f1 5392  df-fo 5393  df-f1o 5394  df-fv 5395  df-ov 6016  df-oprab 6017  df-mpt2 6018  df-1st 6281  df-2nd 6282  df-riota 6478  df-recs 6562  df-rdg 6597  df-er 6834  df-en 7039  df-dom 7040  df-sdom 7041  df-sup 7374  df-pnf 9048  df-mnf 9049  df-xr 9050  df-ltxr 9051  df-le 9052  df-sub 9218  df-neg 9219  df-div 9603  df-nn 9926  df-2 9983  df-3 9984  df-n0 10147  df-z 10208  df-uz 10414  df-q 10500  df-rp 10538  df-seq 11244  df-exp 11303  df-cj 11824  df-re 11825  df-im 11826  df-sqr 11960  df-abs 11961
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