| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 1z | ⊢ 1  ∈  ℤ | 
						
							| 2 |  | nn0z | ⊢ ( 𝑁  ∈  ℕ0  →  𝑁  ∈  ℤ ) | 
						
							| 3 |  | elfz1 | ⊢ ( ( 1  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝑗  ∈  ( 1 ... 𝑁 )  ↔  ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗  ∧  𝑗  ≤  𝑁 ) ) ) | 
						
							| 4 | 1 2 3 | sylancr | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑗  ∈  ( 1 ... 𝑁 )  ↔  ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗  ∧  𝑗  ≤  𝑁 ) ) ) | 
						
							| 5 |  | 3anass | ⊢ ( ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗  ∧  𝑗  ≤  𝑁 )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  𝑗  ≤  𝑁 ) ) ) | 
						
							| 6 | 4 5 | bitrdi | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑗  ∈  ( 1 ... 𝑁 )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  𝑗  ≤  𝑁 ) ) ) ) | 
						
							| 7 | 6 | baibd | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( 𝑗  ∈  ( 1 ... 𝑁 )  ↔  ( 1  ≤  𝑗  ∧  𝑗  ≤  𝑁 ) ) ) | 
						
							| 8 | 7 | baibd | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  1  ≤  𝑗 )  →  ( 𝑗  ∈  ( 1 ... 𝑁 )  ↔  𝑗  ≤  𝑁 ) ) | 
						
							| 9 | 8 | notbid | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  1  ≤  𝑗 )  →  ( ¬  𝑗  ∈  ( 1 ... 𝑁 )  ↔  ¬  𝑗  ≤  𝑁 ) ) | 
						
							| 10 |  | simpl | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  𝑁  ∈  ℤ ) | 
						
							| 11 | 10 | zred | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  𝑁  ∈  ℝ ) | 
						
							| 12 |  | simpr | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  𝑗  ∈  ℤ ) | 
						
							| 13 | 12 | zred | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  𝑗  ∈  ℝ ) | 
						
							| 14 | 11 13 | ltnled | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  ( 𝑁  <  𝑗  ↔  ¬  𝑗  ≤  𝑁 ) ) | 
						
							| 15 |  | zltp1le | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  ( 𝑁  <  𝑗  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 16 | 14 15 | bitr3d | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑗  ∈  ℤ )  →  ( ¬  𝑗  ≤  𝑁  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 17 | 2 16 | sylan | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( ¬  𝑗  ≤  𝑁  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 18 | 17 | adantr | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  1  ≤  𝑗 )  →  ( ¬  𝑗  ≤  𝑁  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 19 | 9 18 | bitrd | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  1  ≤  𝑗 )  →  ( ¬  𝑗  ∈  ( 1 ... 𝑁 )  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 20 | 19 | pm5.32da | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) )  ↔  ( 1  ≤  𝑗  ∧  ( 𝑁  +  1 )  ≤  𝑗 ) ) ) | 
						
							| 21 |  | 1red | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  1  ∈  ℝ ) | 
						
							| 22 |  | simpll | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  𝑁  ∈  ℕ0 ) | 
						
							| 23 | 22 | nn0red | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  𝑁  ∈  ℝ ) | 
						
							| 24 | 23 21 | readdcld | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  ( 𝑁  +  1 )  ∈  ℝ ) | 
						
							| 25 |  | simplr | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  𝑗  ∈  ℤ ) | 
						
							| 26 | 25 | zred | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  𝑗  ∈  ℝ ) | 
						
							| 27 |  | 0p1e1 | ⊢ ( 0  +  1 )  =  1 | 
						
							| 28 |  | 0red | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  0  ∈  ℝ ) | 
						
							| 29 | 22 | nn0ge0d | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  0  ≤  𝑁 ) | 
						
							| 30 | 28 23 21 29 | leadd1dd | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  ( 0  +  1 )  ≤  ( 𝑁  +  1 ) ) | 
						
							| 31 | 27 30 | eqbrtrrid | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  1  ≤  ( 𝑁  +  1 ) ) | 
						
							| 32 |  | simpr | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  ( 𝑁  +  1 )  ≤  𝑗 ) | 
						
							| 33 | 21 24 26 31 32 | letrd | ⊢ ( ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  ∧  ( 𝑁  +  1 )  ≤  𝑗 )  →  1  ≤  𝑗 ) | 
						
							| 34 | 33 | ex | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( ( 𝑁  +  1 )  ≤  𝑗  →  1  ≤  𝑗 ) ) | 
						
							| 35 | 34 | pm4.71rd | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( ( 𝑁  +  1 )  ≤  𝑗  ↔  ( 1  ≤  𝑗  ∧  ( 𝑁  +  1 )  ≤  𝑗 ) ) ) | 
						
							| 36 | 20 35 | bitr4d | ⊢ ( ( 𝑁  ∈  ℕ0  ∧  𝑗  ∈  ℤ )  →  ( ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) )  ↔  ( 𝑁  +  1 )  ≤  𝑗 ) ) | 
						
							| 37 | 36 | pm5.32da | ⊢ ( 𝑁  ∈  ℕ0  →  ( ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 𝑁  +  1 )  ≤  𝑗 ) ) ) | 
						
							| 38 |  | eldif | ⊢ ( 𝑗  ∈  ( ℕ  ∖  ( 1 ... 𝑁 ) )  ↔  ( 𝑗  ∈  ℕ  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) ) | 
						
							| 39 |  | elnnz1 | ⊢ ( 𝑗  ∈  ℕ  ↔  ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗 ) ) | 
						
							| 40 | 39 | anbi1i | ⊢ ( ( 𝑗  ∈  ℕ  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) )  ↔  ( ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗 )  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) ) | 
						
							| 41 |  | anass | ⊢ ( ( ( 𝑗  ∈  ℤ  ∧  1  ≤  𝑗 )  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 42 | 38 40 41 | 3bitri | ⊢ ( 𝑗  ∈  ( ℕ  ∖  ( 1 ... 𝑁 ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 43 | 42 | a1i | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑗  ∈  ( ℕ  ∖  ( 1 ... 𝑁 ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 1  ≤  𝑗  ∧  ¬  𝑗  ∈  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 44 |  | peano2nn0 | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑁  +  1 )  ∈  ℕ0 ) | 
						
							| 45 | 44 | nn0zd | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑁  +  1 )  ∈  ℤ ) | 
						
							| 46 |  | eluz1 | ⊢ ( ( 𝑁  +  1 )  ∈  ℤ  →  ( 𝑗  ∈  ( ℤ≥ ‘ ( 𝑁  +  1 ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 𝑁  +  1 )  ≤  𝑗 ) ) ) | 
						
							| 47 | 45 46 | syl | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑗  ∈  ( ℤ≥ ‘ ( 𝑁  +  1 ) )  ↔  ( 𝑗  ∈  ℤ  ∧  ( 𝑁  +  1 )  ≤  𝑗 ) ) ) | 
						
							| 48 | 37 43 47 | 3bitr4d | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑗  ∈  ( ℕ  ∖  ( 1 ... 𝑁 ) )  ↔  𝑗  ∈  ( ℤ≥ ‘ ( 𝑁  +  1 ) ) ) ) | 
						
							| 49 | 48 | eqrdv | ⊢ ( 𝑁  ∈  ℕ0  →  ( ℕ  ∖  ( 1 ... 𝑁 ) )  =  ( ℤ≥ ‘ ( 𝑁  +  1 ) ) ) |