| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nnnn0 | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ  →  ( 𝑎  /  2 )  ∈  ℕ0 ) | 
						
							| 2 |  | blennn0em1 | ⊢ ( ( 𝑎  ∈  ℕ  ∧  ( 𝑎  /  2 )  ∈  ℕ0 )  →  ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 ) ) | 
						
							| 3 | 1 2 | sylan2 | ⊢ ( ( 𝑎  ∈  ℕ  ∧  ( 𝑎  /  2 )  ∈  ℕ )  →  ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 ) ) | 
						
							| 4 |  | fveqeq2 | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  ( ( #b ‘ 𝑥 )  =  𝑦  ↔  ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦 ) ) | 
						
							| 5 |  | id | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  𝑥  =  ( 𝑎  /  2 ) ) | 
						
							| 6 |  | oveq2 | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  ( 𝑘 ( digit ‘ 2 ) 𝑥 )  =  ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) ) ) | 
						
							| 7 | 6 | oveq1d | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) | 
						
							| 8 | 7 | adantr | ⊢ ( ( 𝑥  =  ( 𝑎  /  2 )  ∧  𝑘  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) | 
						
							| 9 | 8 | sumeq2dv | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) | 
						
							| 10 | 5 9 | eqeq12d | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  ( 𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) )  ↔  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) ) | 
						
							| 11 | 4 10 | imbi12d | ⊢ ( 𝑥  =  ( 𝑎  /  2 )  →  ( ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  ↔  ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) | 
						
							| 12 | 11 | rspcva | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ0  ∧  ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) ) ) | 
						
							| 13 |  | simpr | ⊢ ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  →  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) ) | 
						
							| 14 | 13 | oveq1d | ⊢ ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  →  ( ( #b ‘ 𝑎 )  −  1 )  =  ( ( 𝑦  +  1 )  −  1 ) ) | 
						
							| 15 |  | nncn | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ℂ ) | 
						
							| 16 |  | pncan1 | ⊢ ( 𝑦  ∈  ℂ  →  ( ( 𝑦  +  1 )  −  1 )  =  𝑦 ) | 
						
							| 17 | 15 16 | syl | ⊢ ( 𝑦  ∈  ℕ  →  ( ( 𝑦  +  1 )  −  1 )  =  𝑦 ) | 
						
							| 18 | 14 17 | sylan9eq | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( #b ‘ 𝑎 )  −  1 )  =  𝑦 ) | 
						
							| 19 | 18 | eqeq2d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  ↔  ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦 ) ) | 
						
							| 20 |  | nnz | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ℤ ) | 
						
							| 21 | 20 | adantl | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  𝑦  ∈  ℤ ) | 
						
							| 22 |  | fzval3 | ⊢ ( 𝑦  ∈  ℤ  →  ( 0 ... 𝑦 )  =  ( 0 ..^ ( 𝑦  +  1 ) ) ) | 
						
							| 23 | 21 22 | syl | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0 ... 𝑦 )  =  ( 0 ..^ ( 𝑦  +  1 ) ) ) | 
						
							| 24 | 23 | eqcomd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0 ..^ ( 𝑦  +  1 ) )  =  ( 0 ... 𝑦 ) ) | 
						
							| 25 | 24 | sumeq1d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  Σ 𝑘  ∈  ( 0 ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) | 
						
							| 26 |  | nnnn0 | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ℕ0 ) | 
						
							| 27 |  | elnn0uz | ⊢ ( 𝑦  ∈  ℕ0  ↔  𝑦  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 28 | 26 27 | sylib | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 29 | 28 | adantl | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  𝑦  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 30 |  | 2nn | ⊢ 2  ∈  ℕ | 
						
							| 31 | 30 | a1i | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  2  ∈  ℕ ) | 
						
							| 32 |  | elfzelz | ⊢ ( 𝑘  ∈  ( 0 ... 𝑦 )  →  𝑘  ∈  ℤ ) | 
						
							| 33 | 32 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  𝑘  ∈  ℤ ) | 
						
							| 34 |  | nnnn0 | ⊢ ( 𝑎  ∈  ℕ  →  𝑎  ∈  ℕ0 ) | 
						
							| 35 |  | nn0rp0 | ⊢ ( 𝑎  ∈  ℕ0  →  𝑎  ∈  ( 0 [,) +∞ ) ) | 
						
							| 36 | 34 35 | syl | ⊢ ( 𝑎  ∈  ℕ  →  𝑎  ∈  ( 0 [,) +∞ ) ) | 
						
							| 37 | 36 | ad4antlr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  𝑎  ∈  ( 0 [,) +∞ ) ) | 
						
							| 38 |  | digvalnn0 | ⊢ ( ( 2  ∈  ℕ  ∧  𝑘  ∈  ℤ  ∧  𝑎  ∈  ( 0 [,) +∞ ) )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ∈  ℕ0 ) | 
						
							| 39 | 31 33 37 38 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ∈  ℕ0 ) | 
						
							| 40 | 39 | nn0cnd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ∈  ℂ ) | 
						
							| 41 |  | 2nn0 | ⊢ 2  ∈  ℕ0 | 
						
							| 42 | 41 | a1i | ⊢ ( 𝑘  ∈  ( 0 ... 𝑦 )  →  2  ∈  ℕ0 ) | 
						
							| 43 |  | elfznn0 | ⊢ ( 𝑘  ∈  ( 0 ... 𝑦 )  →  𝑘  ∈  ℕ0 ) | 
						
							| 44 | 42 43 | nn0expcld | ⊢ ( 𝑘  ∈  ( 0 ... 𝑦 )  →  ( 2 ↑ 𝑘 )  ∈  ℕ0 ) | 
						
							| 45 | 44 | nn0cnd | ⊢ ( 𝑘  ∈  ( 0 ... 𝑦 )  →  ( 2 ↑ 𝑘 )  ∈  ℂ ) | 
						
							| 46 | 45 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  ( 2 ↑ 𝑘 )  ∈  ℂ ) | 
						
							| 47 | 40 46 | mulcld | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( 0 ... 𝑦 ) )  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  ∈  ℂ ) | 
						
							| 48 |  | oveq1 | ⊢ ( 𝑘  =  0  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  =  ( 0 ( digit ‘ 2 ) 𝑎 ) ) | 
						
							| 49 |  | oveq2 | ⊢ ( 𝑘  =  0  →  ( 2 ↑ 𝑘 )  =  ( 2 ↑ 0 ) ) | 
						
							| 50 | 48 49 | oveq12d | ⊢ ( 𝑘  =  0  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 0 ) ) ) | 
						
							| 51 |  | 2cn | ⊢ 2  ∈  ℂ | 
						
							| 52 |  | exp0 | ⊢ ( 2  ∈  ℂ  →  ( 2 ↑ 0 )  =  1 ) | 
						
							| 53 | 51 52 | ax-mp | ⊢ ( 2 ↑ 0 )  =  1 | 
						
							| 54 | 53 | oveq2i | ⊢ ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 0 ) )  =  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 ) | 
						
							| 55 | 50 54 | eqtrdi | ⊢ ( 𝑘  =  0  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 ) ) | 
						
							| 56 | 29 47 55 | fsum1p | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑘  ∈  ( 0 ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  +  Σ 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) | 
						
							| 57 |  | 0dig2nn0e | ⊢ ( ( 𝑎  ∈  ℕ0  ∧  ( 𝑎  /  2 )  ∈  ℕ0 )  →  ( 0 ( digit ‘ 2 ) 𝑎 )  =  0 ) | 
						
							| 58 | 34 1 57 | syl2anr | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( 0 ( digit ‘ 2 ) 𝑎 )  =  0 ) | 
						
							| 59 | 58 | oveq1d | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  =  ( 0  ·  1 ) ) | 
						
							| 60 |  | 1re | ⊢ 1  ∈  ℝ | 
						
							| 61 |  | mul02lem2 | ⊢ ( 1  ∈  ℝ  →  ( 0  ·  1 )  =  0 ) | 
						
							| 62 | 60 61 | ax-mp | ⊢ ( 0  ·  1 )  =  0 | 
						
							| 63 | 59 62 | eqtrdi | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  =  0 ) | 
						
							| 64 | 63 | adantr | ⊢ ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  →  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  =  0 ) | 
						
							| 65 | 64 | adantr | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  =  0 ) | 
						
							| 66 |  | 1z | ⊢ 1  ∈  ℤ | 
						
							| 67 | 66 | a1i | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  1  ∈  ℤ ) | 
						
							| 68 |  | 0p1e1 | ⊢ ( 0  +  1 )  =  1 | 
						
							| 69 | 68 66 | eqeltri | ⊢ ( 0  +  1 )  ∈  ℤ | 
						
							| 70 | 69 | a1i | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0  +  1 )  ∈  ℤ ) | 
						
							| 71 | 30 | a1i | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  2  ∈  ℕ ) | 
						
							| 72 |  | elfzelz | ⊢ ( 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 )  →  𝑘  ∈  ℤ ) | 
						
							| 73 | 72 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  𝑘  ∈  ℤ ) | 
						
							| 74 | 36 | ad4antlr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  𝑎  ∈  ( 0 [,) +∞ ) ) | 
						
							| 75 | 71 73 74 38 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ∈  ℕ0 ) | 
						
							| 76 | 75 | nn0cnd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ∈  ℂ ) | 
						
							| 77 |  | 2cnd | ⊢ ( 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 )  →  2  ∈  ℂ ) | 
						
							| 78 |  | elfznn | ⊢ ( 𝑘  ∈  ( 1 ... 𝑦 )  →  𝑘  ∈  ℕ ) | 
						
							| 79 | 78 | nnnn0d | ⊢ ( 𝑘  ∈  ( 1 ... 𝑦 )  →  𝑘  ∈  ℕ0 ) | 
						
							| 80 | 68 | oveq1i | ⊢ ( ( 0  +  1 ) ... 𝑦 )  =  ( 1 ... 𝑦 ) | 
						
							| 81 | 79 80 | eleq2s | ⊢ ( 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 )  →  𝑘  ∈  ℕ0 ) | 
						
							| 82 | 77 81 | expcld | ⊢ ( 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 )  →  ( 2 ↑ 𝑘 )  ∈  ℂ ) | 
						
							| 83 | 82 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  ( 2 ↑ 𝑘 )  ∈  ℂ ) | 
						
							| 84 | 76 83 | mulcld | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) )  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  ∈  ℂ ) | 
						
							| 85 |  | oveq1 | ⊢ ( 𝑘  =  ( 𝑖  +  1 )  →  ( 𝑘 ( digit ‘ 2 ) 𝑎 )  =  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 ) ) | 
						
							| 86 |  | oveq2 | ⊢ ( 𝑘  =  ( 𝑖  +  1 )  →  ( 2 ↑ 𝑘 )  =  ( 2 ↑ ( 𝑖  +  1 ) ) ) | 
						
							| 87 | 85 86 | oveq12d | ⊢ ( 𝑘  =  ( 𝑖  +  1 )  →  ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) | 
						
							| 88 | 67 70 21 84 87 | fsumshftm | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) | 
						
							| 89 | 65 88 | oveq12d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  +  Σ 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) )  =  ( 0  +  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) ) | 
						
							| 90 | 1 | ad4antr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 𝑎  /  2 )  ∈  ℕ0 ) | 
						
							| 91 | 34 | ad4antlr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  𝑎  ∈  ℕ0 ) | 
						
							| 92 |  | elfzonn0 | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  𝑖  ∈  ℕ0 ) | 
						
							| 93 | 92 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  𝑖  ∈  ℕ0 ) | 
						
							| 94 |  | dignn0ehalf | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ0  ∧  𝑎  ∈  ℕ0  ∧  𝑖  ∈  ℕ0 )  →  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  =  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) ) ) | 
						
							| 95 | 90 91 93 94 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  =  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) ) ) | 
						
							| 96 |  | 2cnd | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  2  ∈  ℂ ) | 
						
							| 97 | 96 92 | expp1d | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ ( 𝑖  +  1 ) )  =  ( ( 2 ↑ 𝑖 )  ·  2 ) ) | 
						
							| 98 | 97 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 2 ↑ ( 𝑖  +  1 ) )  =  ( ( 2 ↑ 𝑖 )  ·  2 ) ) | 
						
							| 99 | 95 98 | oveq12d | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  =  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( ( 2 ↑ 𝑖 )  ·  2 ) ) ) | 
						
							| 100 | 30 | a1i | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  2  ∈  ℕ ) | 
						
							| 101 |  | elfzoelz | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  𝑖  ∈  ℤ ) | 
						
							| 102 | 101 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  𝑖  ∈  ℤ ) | 
						
							| 103 |  | nn0rp0 | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ0  →  ( 𝑎  /  2 )  ∈  ( 0 [,) +∞ ) ) | 
						
							| 104 | 1 103 | syl | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ  →  ( 𝑎  /  2 )  ∈  ( 0 [,) +∞ ) ) | 
						
							| 105 | 104 | ad4antr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 𝑎  /  2 )  ∈  ( 0 [,) +∞ ) ) | 
						
							| 106 |  | digvalnn0 | ⊢ ( ( 2  ∈  ℕ  ∧  𝑖  ∈  ℤ  ∧  ( 𝑎  /  2 )  ∈  ( 0 [,) +∞ ) )  →  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ∈  ℕ0 ) | 
						
							| 107 | 100 102 105 106 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ∈  ℕ0 ) | 
						
							| 108 | 107 | nn0cnd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ∈  ℂ ) | 
						
							| 109 |  | 2re | ⊢ 2  ∈  ℝ | 
						
							| 110 | 109 | a1i | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  2  ∈  ℝ ) | 
						
							| 111 | 110 92 | reexpcld | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ 𝑖 )  ∈  ℝ ) | 
						
							| 112 | 111 | recnd | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ 𝑖 )  ∈  ℂ ) | 
						
							| 113 | 112 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 2 ↑ 𝑖 )  ∈  ℂ ) | 
						
							| 114 |  | 2cnd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  2  ∈  ℂ ) | 
						
							| 115 |  | mulass | ⊢ ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ∈  ℂ  ∧  ( 2 ↑ 𝑖 )  ∈  ℂ  ∧  2  ∈  ℂ )  →  ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 )  =  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( ( 2 ↑ 𝑖 )  ·  2 ) ) ) | 
						
							| 116 | 115 | eqcomd | ⊢ ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ∈  ℂ  ∧  ( 2 ↑ 𝑖 )  ∈  ℂ  ∧  2  ∈  ℂ )  →  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( ( 2 ↑ 𝑖 )  ·  2 ) )  =  ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 117 | 108 113 114 116 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( ( 2 ↑ 𝑖 )  ·  2 ) )  =  ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 118 | 99 117 | eqtrd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  =  ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 119 | 118 | sumeq2dv | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 120 |  | 0cn | ⊢ 0  ∈  ℂ | 
						
							| 121 |  | pncan1 | ⊢ ( 0  ∈  ℂ  →  ( ( 0  +  1 )  −  1 )  =  0 ) | 
						
							| 122 | 120 121 | ax-mp | ⊢ ( ( 0  +  1 )  −  1 )  =  0 | 
						
							| 123 | 122 | a1i | ⊢ ( 𝑦  ∈  ℕ  →  ( ( 0  +  1 )  −  1 )  =  0 ) | 
						
							| 124 | 123 | oveq1d | ⊢ ( 𝑦  ∈  ℕ  →  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) )  =  ( 0 ... ( 𝑦  −  1 ) ) ) | 
						
							| 125 |  | fzoval | ⊢ ( 𝑦  ∈  ℤ  →  ( 0 ..^ 𝑦 )  =  ( 0 ... ( 𝑦  −  1 ) ) ) | 
						
							| 126 | 125 | eqcomd | ⊢ ( 𝑦  ∈  ℤ  →  ( 0 ... ( 𝑦  −  1 ) )  =  ( 0 ..^ 𝑦 ) ) | 
						
							| 127 | 20 126 | syl | ⊢ ( 𝑦  ∈  ℕ  →  ( 0 ... ( 𝑦  −  1 ) )  =  ( 0 ..^ 𝑦 ) ) | 
						
							| 128 | 124 127 | eqtrd | ⊢ ( 𝑦  ∈  ℕ  →  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) )  =  ( 0 ..^ 𝑦 ) ) | 
						
							| 129 | 128 | adantl | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) )  =  ( 0 ..^ 𝑦 ) ) | 
						
							| 130 | 129 | sumeq1d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) | 
						
							| 131 | 130 | oveq2d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0  +  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) )  =  ( 0  +  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) ) | 
						
							| 132 |  | fzofi | ⊢ ( 0 ..^ 𝑦 )  ∈  Fin | 
						
							| 133 | 132 | a1i | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0 ..^ 𝑦 )  ∈  Fin ) | 
						
							| 134 | 101 | peano2zd | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 𝑖  +  1 )  ∈  ℤ ) | 
						
							| 135 | 134 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 𝑖  +  1 )  ∈  ℤ ) | 
						
							| 136 | 36 | ad4antlr | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  𝑎  ∈  ( 0 [,) +∞ ) ) | 
						
							| 137 |  | digvalnn0 | ⊢ ( ( 2  ∈  ℕ  ∧  ( 𝑖  +  1 )  ∈  ℤ  ∧  𝑎  ∈  ( 0 [,) +∞ ) )  →  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ∈  ℕ0 ) | 
						
							| 138 | 100 135 136 137 | syl3anc | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ∈  ℕ0 ) | 
						
							| 139 | 138 | nn0cnd | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ∈  ℂ ) | 
						
							| 140 | 41 | a1i | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  2  ∈  ℕ0 ) | 
						
							| 141 |  | peano2nn0 | ⊢ ( 𝑖  ∈  ℕ0  →  ( 𝑖  +  1 )  ∈  ℕ0 ) | 
						
							| 142 | 92 141 | syl | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 𝑖  +  1 )  ∈  ℕ0 ) | 
						
							| 143 | 140 142 | nn0expcld | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ ( 𝑖  +  1 ) )  ∈  ℕ0 ) | 
						
							| 144 | 143 | nn0cnd | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ ( 𝑖  +  1 ) )  ∈  ℂ ) | 
						
							| 145 | 144 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 2 ↑ ( 𝑖  +  1 ) )  ∈  ℂ ) | 
						
							| 146 | 139 145 | mulcld | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  ∈  ℂ ) | 
						
							| 147 | 133 146 | fsumcl | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) )  ∈  ℂ ) | 
						
							| 148 | 147 | addlidd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0  +  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) | 
						
							| 149 | 131 148 | eqtrd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0  +  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) ) | 
						
							| 150 |  | 2cnd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  2  ∈  ℂ ) | 
						
							| 151 | 140 92 | nn0expcld | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ 𝑖 )  ∈  ℕ0 ) | 
						
							| 152 | 151 | nn0cnd | ⊢ ( 𝑖  ∈  ( 0 ..^ 𝑦 )  →  ( 2 ↑ 𝑖 )  ∈  ℂ ) | 
						
							| 153 | 152 | adantl | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( 2 ↑ 𝑖 )  ∈  ℂ ) | 
						
							| 154 | 108 153 | mulcld | ⊢ ( ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  ∧  𝑖  ∈  ( 0 ..^ 𝑦 ) )  →  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ∈  ℂ ) | 
						
							| 155 | 133 150 154 | fsummulc1 | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 156 | 119 149 155 | 3eqtr4d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( 0  +  Σ 𝑖  ∈  ( ( ( 0  +  1 )  −  1 ) ... ( 𝑦  −  1 ) ) ( ( ( 𝑖  +  1 ) ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ ( 𝑖  +  1 ) ) ) )  =  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 157 | 89 156 | eqtrd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( ( 0 ( digit ‘ 2 ) 𝑎 )  ·  1 )  +  Σ 𝑘  ∈  ( ( 0  +  1 ) ... 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) )  =  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 158 | 25 56 157 | 3eqtrd | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 159 | 158 | adantl | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) )  =  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 ) ) | 
						
							| 160 |  | oveq1 | ⊢ ( 𝑘  =  𝑖  →  ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  =  ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) ) ) | 
						
							| 161 |  | oveq2 | ⊢ ( 𝑘  =  𝑖  →  ( 2 ↑ 𝑘 )  =  ( 2 ↑ 𝑖 ) ) | 
						
							| 162 | 160 161 | oveq12d | ⊢ ( 𝑘  =  𝑖  →  ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  =  ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) ) ) | 
						
							| 163 | 162 | cbvsumv | ⊢ Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) ) | 
						
							| 164 | 163 | a1i | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) ) ) | 
						
							| 165 | 164 | eqeq2d | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ↔  ( 𝑎  /  2 )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) ) ) ) | 
						
							| 166 | 165 | biimpac | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  ( 𝑎  /  2 )  =  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) ) ) | 
						
							| 167 | 166 | eqcomd | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  =  ( 𝑎  /  2 ) ) | 
						
							| 168 | 167 | oveq1d | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  ( Σ 𝑖  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑖 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑖 ) )  ·  2 )  =  ( ( 𝑎  /  2 )  ·  2 ) ) | 
						
							| 169 |  | nncn | ⊢ ( 𝑎  ∈  ℕ  →  𝑎  ∈  ℂ ) | 
						
							| 170 |  | 2cnd | ⊢ ( 𝑎  ∈  ℕ  →  2  ∈  ℂ ) | 
						
							| 171 |  | 2ne0 | ⊢ 2  ≠  0 | 
						
							| 172 | 171 | a1i | ⊢ ( 𝑎  ∈  ℕ  →  2  ≠  0 ) | 
						
							| 173 | 169 170 172 | divcan1d | ⊢ ( 𝑎  ∈  ℕ  →  ( ( 𝑎  /  2 )  ·  2 )  =  𝑎 ) | 
						
							| 174 | 173 | ad3antlr | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( 𝑎  /  2 )  ·  2 )  =  𝑎 ) | 
						
							| 175 | 174 | adantl | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  ( ( 𝑎  /  2 )  ·  2 )  =  𝑎 ) | 
						
							| 176 | 159 168 175 | 3eqtrrd | ⊢ ( ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  ∧  ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ ) )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) | 
						
							| 177 | 176 | ex | ⊢ ( ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) )  →  ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) | 
						
							| 178 | 177 | imim2i | ⊢ ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) | 
						
							| 179 | 178 | com13 | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) | 
						
							| 180 | 19 179 | sylbid | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) | 
						
							| 181 | 180 | com23 | ⊢ ( ( ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  ∧  ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 ) )  ∧  𝑦  ∈  ℕ )  →  ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) | 
						
							| 182 | 181 | exp31 | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  ( 𝑦  ∈  ℕ  →  ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) | 
						
							| 183 | 182 | com25 | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) | 
						
							| 184 | 183 | com14 | ⊢ ( ( ( #b ‘ ( 𝑎  /  2 ) )  =  𝑦  →  ( 𝑎  /  2 )  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) ( 𝑎  /  2 ) )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) | 
						
							| 185 | 12 184 | syl | ⊢ ( ( ( 𝑎  /  2 )  ∈  ℕ0  ∧  ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) | 
						
							| 186 | 185 | ex | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ0  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) ) | 
						
							| 187 | 186 | com25 | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ0  →  ( ( ( 𝑎  /  2 )  ∈  ℕ  ∧  𝑎  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) ) | 
						
							| 188 | 187 | expdcom | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ  →  ( 𝑎  ∈  ℕ  →  ( ( 𝑎  /  2 )  ∈  ℕ0  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) ) ) | 
						
							| 189 | 1 188 | mpid | ⊢ ( ( 𝑎  /  2 )  ∈  ℕ  →  ( 𝑎  ∈  ℕ  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) ) | 
						
							| 190 | 189 | impcom | ⊢ ( ( 𝑎  ∈  ℕ  ∧  ( 𝑎  /  2 )  ∈  ℕ )  →  ( ( #b ‘ ( 𝑎  /  2 ) )  =  ( ( #b ‘ 𝑎 )  −  1 )  →  ( 𝑦  ∈  ℕ  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) ) | 
						
							| 191 | 3 190 | mpd | ⊢ ( ( 𝑎  ∈  ℕ  ∧  ( 𝑎  /  2 )  ∈  ℕ )  →  ( 𝑦  ∈  ℕ  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) ) | 
						
							| 192 | 191 | imp | ⊢ ( ( ( 𝑎  ∈  ℕ  ∧  ( 𝑎  /  2 )  ∈  ℕ )  ∧  𝑦  ∈  ℕ )  →  ( ∀ 𝑥  ∈  ℕ0 ( ( #b ‘ 𝑥 )  =  𝑦  →  𝑥  =  Σ 𝑘  ∈  ( 0 ..^ 𝑦 ) ( ( 𝑘 ( digit ‘ 2 ) 𝑥 )  ·  ( 2 ↑ 𝑘 ) ) )  →  ( ( #b ‘ 𝑎 )  =  ( 𝑦  +  1 )  →  𝑎  =  Σ 𝑘  ∈  ( 0 ..^ ( 𝑦  +  1 ) ) ( ( 𝑘 ( digit ‘ 2 ) 𝑎 )  ·  ( 2 ↑ 𝑘 ) ) ) ) ) |