This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Lemma for odd2np1 . (Contributed by Scott Fenton, 3-Apr-2014) (Revised by Mario Carneiro, 19-Apr-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | odd2np1lem | ⊢ ( 𝑁 ∈ ℕ0 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑁 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑁 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqeq2 | ⊢ ( 𝑗 = 0 → ( ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ( ( 2 · 𝑛 ) + 1 ) = 0 ) ) | |
| 2 | 1 | rexbidv | ⊢ ( 𝑗 = 0 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 0 ) ) |
| 3 | eqeq2 | ⊢ ( 𝑗 = 0 → ( ( 𝑘 · 2 ) = 𝑗 ↔ ( 𝑘 · 2 ) = 0 ) ) | |
| 4 | 3 | rexbidv | ⊢ ( 𝑗 = 0 → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ↔ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 0 ) ) |
| 5 | 2 4 | orbi12d | ⊢ ( 𝑗 = 0 → ( ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ) ↔ ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 0 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 0 ) ) ) |
| 6 | eqeq2 | ⊢ ( 𝑗 = 𝑚 → ( ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ( ( 2 · 𝑛 ) + 1 ) = 𝑚 ) ) | |
| 7 | 6 | rexbidv | ⊢ ( 𝑗 = 𝑚 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑚 ) ) |
| 8 | oveq2 | ⊢ ( 𝑛 = 𝑥 → ( 2 · 𝑛 ) = ( 2 · 𝑥 ) ) | |
| 9 | 8 | oveq1d | ⊢ ( 𝑛 = 𝑥 → ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑥 ) + 1 ) ) |
| 10 | 9 | eqeq1d | ⊢ ( 𝑛 = 𝑥 → ( ( ( 2 · 𝑛 ) + 1 ) = 𝑚 ↔ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ) ) |
| 11 | 10 | cbvrexvw | ⊢ ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑚 ↔ ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ) |
| 12 | 7 11 | bitrdi | ⊢ ( 𝑗 = 𝑚 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ) ) |
| 13 | eqeq2 | ⊢ ( 𝑗 = 𝑚 → ( ( 𝑘 · 2 ) = 𝑗 ↔ ( 𝑘 · 2 ) = 𝑚 ) ) | |
| 14 | 13 | rexbidv | ⊢ ( 𝑗 = 𝑚 → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ↔ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑚 ) ) |
| 15 | oveq1 | ⊢ ( 𝑘 = 𝑦 → ( 𝑘 · 2 ) = ( 𝑦 · 2 ) ) | |
| 16 | 15 | eqeq1d | ⊢ ( 𝑘 = 𝑦 → ( ( 𝑘 · 2 ) = 𝑚 ↔ ( 𝑦 · 2 ) = 𝑚 ) ) |
| 17 | 16 | cbvrexvw | ⊢ ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑚 ↔ ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ) |
| 18 | 14 17 | bitrdi | ⊢ ( 𝑗 = 𝑚 → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ↔ ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ) ) |
| 19 | 12 18 | orbi12d | ⊢ ( 𝑗 = 𝑚 → ( ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ) ↔ ( ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ∨ ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ) ) ) |
| 20 | eqeq2 | ⊢ ( 𝑗 = ( 𝑚 + 1 ) → ( ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) | |
| 21 | 20 | rexbidv | ⊢ ( 𝑗 = ( 𝑚 + 1 ) → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 22 | eqeq2 | ⊢ ( 𝑗 = ( 𝑚 + 1 ) → ( ( 𝑘 · 2 ) = 𝑗 ↔ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) | |
| 23 | 22 | rexbidv | ⊢ ( 𝑗 = ( 𝑚 + 1 ) → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ↔ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) |
| 24 | 21 23 | orbi12d | ⊢ ( 𝑗 = ( 𝑚 + 1 ) → ( ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ) ↔ ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) ) |
| 25 | eqeq2 | ⊢ ( 𝑗 = 𝑁 → ( ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ( ( 2 · 𝑛 ) + 1 ) = 𝑁 ) ) | |
| 26 | 25 | rexbidv | ⊢ ( 𝑗 = 𝑁 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ↔ ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑁 ) ) |
| 27 | eqeq2 | ⊢ ( 𝑗 = 𝑁 → ( ( 𝑘 · 2 ) = 𝑗 ↔ ( 𝑘 · 2 ) = 𝑁 ) ) | |
| 28 | 27 | rexbidv | ⊢ ( 𝑗 = 𝑁 → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ↔ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑁 ) ) |
| 29 | 26 28 | orbi12d | ⊢ ( 𝑗 = 𝑁 → ( ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑗 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑗 ) ↔ ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑁 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑁 ) ) ) |
| 30 | 0z | ⊢ 0 ∈ ℤ | |
| 31 | 2cn | ⊢ 2 ∈ ℂ | |
| 32 | 31 | mul02i | ⊢ ( 0 · 2 ) = 0 |
| 33 | oveq1 | ⊢ ( 𝑘 = 0 → ( 𝑘 · 2 ) = ( 0 · 2 ) ) | |
| 34 | 33 | eqeq1d | ⊢ ( 𝑘 = 0 → ( ( 𝑘 · 2 ) = 0 ↔ ( 0 · 2 ) = 0 ) ) |
| 35 | 34 | rspcev | ⊢ ( ( 0 ∈ ℤ ∧ ( 0 · 2 ) = 0 ) → ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 0 ) |
| 36 | 30 32 35 | mp2an | ⊢ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 0 |
| 37 | 36 | olci | ⊢ ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 0 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 0 ) |
| 38 | orcom | ⊢ ( ( ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ∨ ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ) ↔ ( ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ∨ ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ) ) | |
| 39 | zcn | ⊢ ( 𝑦 ∈ ℤ → 𝑦 ∈ ℂ ) | |
| 40 | mulcom | ⊢ ( ( 𝑦 ∈ ℂ ∧ 2 ∈ ℂ ) → ( 𝑦 · 2 ) = ( 2 · 𝑦 ) ) | |
| 41 | 39 31 40 | sylancl | ⊢ ( 𝑦 ∈ ℤ → ( 𝑦 · 2 ) = ( 2 · 𝑦 ) ) |
| 42 | 41 | adantl | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑦 ∈ ℤ ) → ( 𝑦 · 2 ) = ( 2 · 𝑦 ) ) |
| 43 | 42 | eqeq1d | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑦 ∈ ℤ ) → ( ( 𝑦 · 2 ) = 𝑚 ↔ ( 2 · 𝑦 ) = 𝑚 ) ) |
| 44 | eqid | ⊢ ( ( 2 · 𝑦 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) | |
| 45 | oveq2 | ⊢ ( 𝑛 = 𝑦 → ( 2 · 𝑛 ) = ( 2 · 𝑦 ) ) | |
| 46 | 45 | oveq1d | ⊢ ( 𝑛 = 𝑦 → ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ) |
| 47 | 46 | eqeq1d | ⊢ ( 𝑛 = 𝑦 → ( ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ↔ ( ( 2 · 𝑦 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ) ) |
| 48 | 47 | rspcev | ⊢ ( ( 𝑦 ∈ ℤ ∧ ( ( 2 · 𝑦 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ) → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ) |
| 49 | 44 48 | mpan2 | ⊢ ( 𝑦 ∈ ℤ → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ) |
| 50 | oveq1 | ⊢ ( ( 2 · 𝑦 ) = 𝑚 → ( ( 2 · 𝑦 ) + 1 ) = ( 𝑚 + 1 ) ) | |
| 51 | 50 | eqeq2d | ⊢ ( ( 2 · 𝑦 ) = 𝑚 → ( ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ↔ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 52 | 51 | rexbidv | ⊢ ( ( 2 · 𝑦 ) = 𝑚 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( ( 2 · 𝑦 ) + 1 ) ↔ ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 53 | 49 52 | syl5ibcom | ⊢ ( 𝑦 ∈ ℤ → ( ( 2 · 𝑦 ) = 𝑚 → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 54 | 53 | adantl | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑦 ∈ ℤ ) → ( ( 2 · 𝑦 ) = 𝑚 → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 55 | 43 54 | sylbid | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑦 ∈ ℤ ) → ( ( 𝑦 · 2 ) = 𝑚 → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 56 | 55 | rexlimdva | ⊢ ( 𝑚 ∈ ℕ0 → ( ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 → ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ) ) |
| 57 | peano2z | ⊢ ( 𝑥 ∈ ℤ → ( 𝑥 + 1 ) ∈ ℤ ) | |
| 58 | zcn | ⊢ ( 𝑥 ∈ ℤ → 𝑥 ∈ ℂ ) | |
| 59 | mulcom | ⊢ ( ( 𝑥 ∈ ℂ ∧ 2 ∈ ℂ ) → ( 𝑥 · 2 ) = ( 2 · 𝑥 ) ) | |
| 60 | 31 59 | mpan2 | ⊢ ( 𝑥 ∈ ℂ → ( 𝑥 · 2 ) = ( 2 · 𝑥 ) ) |
| 61 | 31 | mullidi | ⊢ ( 1 · 2 ) = 2 |
| 62 | 61 | a1i | ⊢ ( 𝑥 ∈ ℂ → ( 1 · 2 ) = 2 ) |
| 63 | 60 62 | oveq12d | ⊢ ( 𝑥 ∈ ℂ → ( ( 𝑥 · 2 ) + ( 1 · 2 ) ) = ( ( 2 · 𝑥 ) + 2 ) ) |
| 64 | df-2 | ⊢ 2 = ( 1 + 1 ) | |
| 65 | 64 | oveq2i | ⊢ ( ( 2 · 𝑥 ) + 2 ) = ( ( 2 · 𝑥 ) + ( 1 + 1 ) ) |
| 66 | 63 65 | eqtrdi | ⊢ ( 𝑥 ∈ ℂ → ( ( 𝑥 · 2 ) + ( 1 · 2 ) ) = ( ( 2 · 𝑥 ) + ( 1 + 1 ) ) ) |
| 67 | ax-1cn | ⊢ 1 ∈ ℂ | |
| 68 | adddir | ⊢ ( ( 𝑥 ∈ ℂ ∧ 1 ∈ ℂ ∧ 2 ∈ ℂ ) → ( ( 𝑥 + 1 ) · 2 ) = ( ( 𝑥 · 2 ) + ( 1 · 2 ) ) ) | |
| 69 | 67 31 68 | mp3an23 | ⊢ ( 𝑥 ∈ ℂ → ( ( 𝑥 + 1 ) · 2 ) = ( ( 𝑥 · 2 ) + ( 1 · 2 ) ) ) |
| 70 | mulcl | ⊢ ( ( 2 ∈ ℂ ∧ 𝑥 ∈ ℂ ) → ( 2 · 𝑥 ) ∈ ℂ ) | |
| 71 | 31 70 | mpan | ⊢ ( 𝑥 ∈ ℂ → ( 2 · 𝑥 ) ∈ ℂ ) |
| 72 | addass | ⊢ ( ( ( 2 · 𝑥 ) ∈ ℂ ∧ 1 ∈ ℂ ∧ 1 ∈ ℂ ) → ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) = ( ( 2 · 𝑥 ) + ( 1 + 1 ) ) ) | |
| 73 | 67 67 72 | mp3an23 | ⊢ ( ( 2 · 𝑥 ) ∈ ℂ → ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) = ( ( 2 · 𝑥 ) + ( 1 + 1 ) ) ) |
| 74 | 71 73 | syl | ⊢ ( 𝑥 ∈ ℂ → ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) = ( ( 2 · 𝑥 ) + ( 1 + 1 ) ) ) |
| 75 | 66 69 74 | 3eqtr4d | ⊢ ( 𝑥 ∈ ℂ → ( ( 𝑥 + 1 ) · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) |
| 76 | 58 75 | syl | ⊢ ( 𝑥 ∈ ℤ → ( ( 𝑥 + 1 ) · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) |
| 77 | 76 | adantl | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑥 ∈ ℤ ) → ( ( 𝑥 + 1 ) · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) |
| 78 | oveq1 | ⊢ ( 𝑘 = ( 𝑥 + 1 ) → ( 𝑘 · 2 ) = ( ( 𝑥 + 1 ) · 2 ) ) | |
| 79 | 78 | eqeq1d | ⊢ ( 𝑘 = ( 𝑥 + 1 ) → ( ( 𝑘 · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ↔ ( ( 𝑥 + 1 ) · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) ) |
| 80 | 79 | rspcev | ⊢ ( ( ( 𝑥 + 1 ) ∈ ℤ ∧ ( ( 𝑥 + 1 ) · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) → ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) |
| 81 | 57 77 80 | syl2an2 | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑥 ∈ ℤ ) → ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ) |
| 82 | oveq1 | ⊢ ( ( ( 2 · 𝑥 ) + 1 ) = 𝑚 → ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) = ( 𝑚 + 1 ) ) | |
| 83 | 82 | eqeq2d | ⊢ ( ( ( 2 · 𝑥 ) + 1 ) = 𝑚 → ( ( 𝑘 · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ↔ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) |
| 84 | 83 | rexbidv | ⊢ ( ( ( 2 · 𝑥 ) + 1 ) = 𝑚 → ( ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( ( ( 2 · 𝑥 ) + 1 ) + 1 ) ↔ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) |
| 85 | 81 84 | syl5ibcom | ⊢ ( ( 𝑚 ∈ ℕ0 ∧ 𝑥 ∈ ℤ ) → ( ( ( 2 · 𝑥 ) + 1 ) = 𝑚 → ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) |
| 86 | 85 | rexlimdva | ⊢ ( 𝑚 ∈ ℕ0 → ( ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 → ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) |
| 87 | 56 86 | orim12d | ⊢ ( 𝑚 ∈ ℕ0 → ( ( ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ∨ ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ) → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) ) |
| 88 | 38 87 | biimtrid | ⊢ ( 𝑚 ∈ ℕ0 → ( ( ∃ 𝑥 ∈ ℤ ( ( 2 · 𝑥 ) + 1 ) = 𝑚 ∨ ∃ 𝑦 ∈ ℤ ( 𝑦 · 2 ) = 𝑚 ) → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = ( 𝑚 + 1 ) ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = ( 𝑚 + 1 ) ) ) ) |
| 89 | 5 19 24 29 37 88 | nn0ind | ⊢ ( 𝑁 ∈ ℕ0 → ( ∃ 𝑛 ∈ ℤ ( ( 2 · 𝑛 ) + 1 ) = 𝑁 ∨ ∃ 𝑘 ∈ ℤ ( 𝑘 · 2 ) = 𝑁 ) ) |