| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2sqnn | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∃ 𝑥  ∈  ℕ ∃ 𝑦  ∈  ℕ 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 2 |  | simpll | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  ∈  ℕ ) | 
						
							| 3 | 2 | adantl | ⊢ ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  𝑥  ∈  ℕ ) | 
						
							| 4 |  | breq1 | ⊢ ( 𝑎  =  𝑥  →  ( 𝑎  ≤  𝑏  ↔  𝑥  ≤  𝑏 ) ) | 
						
							| 5 |  | oveq1 | ⊢ ( 𝑎  =  𝑥  →  ( 𝑎 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) | 
						
							| 6 | 5 | oveq1d | ⊢ ( 𝑎  =  𝑥  →  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) ) ) | 
						
							| 7 | 6 | eqeq1d | ⊢ ( 𝑎  =  𝑥  →  ( ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃  ↔  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 8 | 4 7 | anbi12d | ⊢ ( 𝑎  =  𝑥  →  ( ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 9 | 8 | reubidv | ⊢ ( 𝑎  =  𝑥  →  ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 10 | 9 | adantl | ⊢ ( ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  ∧  𝑎  =  𝑥 )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 11 |  | simpr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  𝑦  ∈  ℕ ) | 
						
							| 12 | 11 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  𝑦  ∈  ℕ ) | 
						
							| 13 |  | breq2 | ⊢ ( 𝑏  =  𝑦  →  ( 𝑥  ≤  𝑏  ↔  𝑥  ≤  𝑦 ) ) | 
						
							| 14 |  | oveq1 | ⊢ ( 𝑏  =  𝑦  →  ( 𝑏 ↑ 2 )  =  ( 𝑦 ↑ 2 ) ) | 
						
							| 15 | 14 | oveq2d | ⊢ ( 𝑏  =  𝑦  →  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 16 | 15 | eqeq1d | ⊢ ( 𝑏  =  𝑦  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 17 | 13 16 | anbi12d | ⊢ ( 𝑏  =  𝑦  →  ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 18 |  | equequ1 | ⊢ ( 𝑏  =  𝑦  →  ( 𝑏  =  𝑐  ↔  𝑦  =  𝑐 ) ) | 
						
							| 19 | 18 | imbi2d | ⊢ ( 𝑏  =  𝑦  →  ( ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 )  ↔  ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) ) | 
						
							| 20 | 19 | ralbidv | ⊢ ( 𝑏  =  𝑦  →  ( ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 )  ↔  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) ) | 
						
							| 21 | 17 20 | anbi12d | ⊢ ( 𝑏  =  𝑦  →  ( ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) )  ↔  ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) ) ) | 
						
							| 22 | 21 | adantl | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑏  =  𝑦 )  →  ( ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) )  ↔  ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) ) ) | 
						
							| 23 |  | simpr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  𝑥  ≤  𝑦 ) | 
						
							| 24 |  | eqidd | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 25 |  | nnre | ⊢ ( 𝑐  ∈  ℕ  →  𝑐  ∈  ℝ ) | 
						
							| 26 | 25 | resqcld | ⊢ ( 𝑐  ∈  ℕ  →  ( 𝑐 ↑ 2 )  ∈  ℝ ) | 
						
							| 27 | 26 | adantl | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( 𝑐 ↑ 2 )  ∈  ℝ ) | 
						
							| 28 |  | nnre | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ℝ ) | 
						
							| 29 | 28 | resqcld | ⊢ ( 𝑦  ∈  ℕ  →  ( 𝑦 ↑ 2 )  ∈  ℝ ) | 
						
							| 30 | 29 | adantl | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℝ ) | 
						
							| 31 | 30 | ad2antrr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℝ ) | 
						
							| 32 |  | nnre | ⊢ ( 𝑥  ∈  ℕ  →  𝑥  ∈  ℝ ) | 
						
							| 33 | 32 | resqcld | ⊢ ( 𝑥  ∈  ℕ  →  ( 𝑥 ↑ 2 )  ∈  ℝ ) | 
						
							| 34 | 33 | adantr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℝ ) | 
						
							| 35 | 34 | ad2antrr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℝ ) | 
						
							| 36 |  | readdcan | ⊢ ( ( ( 𝑐 ↑ 2 )  ∈  ℝ  ∧  ( 𝑦 ↑ 2 )  ∈  ℝ  ∧  ( 𝑥 ↑ 2 )  ∈  ℝ )  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 37 | 27 31 35 36 | syl3anc | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 38 | 28 | ad4antlr | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  𝑦  ∈  ℝ ) | 
						
							| 39 | 25 | ad2antlr | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  𝑐  ∈  ℝ ) | 
						
							| 40 |  | nnnn0 | ⊢ ( 𝑦  ∈  ℕ  →  𝑦  ∈  ℕ0 ) | 
						
							| 41 | 40 | nn0ge0d | ⊢ ( 𝑦  ∈  ℕ  →  0  ≤  𝑦 ) | 
						
							| 42 | 41 | ad4antlr | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  0  ≤  𝑦 ) | 
						
							| 43 |  | nnnn0 | ⊢ ( 𝑐  ∈  ℕ  →  𝑐  ∈  ℕ0 ) | 
						
							| 44 | 43 | nn0ge0d | ⊢ ( 𝑐  ∈  ℕ  →  0  ≤  𝑐 ) | 
						
							| 45 | 44 | ad2antlr | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  0  ≤  𝑐 ) | 
						
							| 46 |  | simpr | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) ) | 
						
							| 47 | 46 | eqcomd | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  ( 𝑦 ↑ 2 )  =  ( 𝑐 ↑ 2 ) ) | 
						
							| 48 | 38 39 42 45 47 | sq11d | ⊢ ( ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 ) )  →  𝑦  =  𝑐 ) | 
						
							| 49 | 48 | ex | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( ( 𝑐 ↑ 2 )  =  ( 𝑦 ↑ 2 )  →  𝑦  =  𝑐 ) ) | 
						
							| 50 | 37 49 | sylbid | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  𝑦  =  𝑐 ) ) | 
						
							| 51 | 50 | adantld | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  ∧  𝑐  ∈  ℕ )  →  ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) | 
						
							| 52 | 51 | ralrimiva | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) | 
						
							| 53 | 23 24 52 | jca31 | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  =  𝑐 ) ) ) | 
						
							| 54 | 12 22 53 | rspcedvd | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  ∃ 𝑏  ∈  ℕ ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) ) ) | 
						
							| 55 |  | breq2 | ⊢ ( 𝑏  =  𝑐  →  ( 𝑥  ≤  𝑏  ↔  𝑥  ≤  𝑐 ) ) | 
						
							| 56 |  | oveq1 | ⊢ ( 𝑏  =  𝑐  →  ( 𝑏 ↑ 2 )  =  ( 𝑐 ↑ 2 ) ) | 
						
							| 57 | 56 | oveq2d | ⊢ ( 𝑏  =  𝑐  →  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) ) ) | 
						
							| 58 | 57 | eqeq1d | ⊢ ( 𝑏  =  𝑐  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 59 | 55 58 | anbi12d | ⊢ ( 𝑏  =  𝑐  →  ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 60 | 59 | reu8 | ⊢ ( ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ∃ 𝑏  ∈  ℕ ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑥  ≤  𝑐  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) ) ) | 
						
							| 61 | 54 60 | sylibr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑥  ≤  𝑦 )  →  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 62 | 61 | ex | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑥  ≤  𝑦  →  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 63 | 62 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  ( 𝑥  ≤  𝑦  →  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 64 | 63 | impcom | ⊢ ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 65 |  | eqeq2 | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃  ↔  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 66 | 65 | anbi2d | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 67 | 66 | reubidv | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 68 | 67 | adantl | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 69 | 68 | adantl | ⊢ ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 70 | 64 69 | mpbird | ⊢ ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃! 𝑏  ∈  ℕ ( 𝑥  ≤  𝑏  ∧  ( ( 𝑥 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 71 | 3 10 70 | rspcedvd | ⊢ ( ( 𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 72 | 11 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑦  ∈  ℕ ) | 
						
							| 73 | 72 | adantl | ⊢ ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  𝑦  ∈  ℕ ) | 
						
							| 74 |  | breq1 | ⊢ ( 𝑎  =  𝑦  →  ( 𝑎  ≤  𝑏  ↔  𝑦  ≤  𝑏 ) ) | 
						
							| 75 |  | oveq1 | ⊢ ( 𝑎  =  𝑦  →  ( 𝑎 ↑ 2 )  =  ( 𝑦 ↑ 2 ) ) | 
						
							| 76 | 75 | oveq1d | ⊢ ( 𝑎  =  𝑦  →  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) ) ) | 
						
							| 77 | 76 | eqeq1d | ⊢ ( 𝑎  =  𝑦  →  ( ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃  ↔  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 78 | 74 77 | anbi12d | ⊢ ( 𝑎  =  𝑦  →  ( ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 79 | 78 | reubidv | ⊢ ( 𝑎  =  𝑦  →  ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 80 | 79 | adantl | ⊢ ( ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  ∧  𝑎  =  𝑦 )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 81 |  | simpll | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  𝑥  ∈  ℕ ) | 
						
							| 82 |  | breq2 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑦  ≤  𝑏  ↔  𝑦  ≤  𝑥 ) ) | 
						
							| 83 |  | oveq1 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑏 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) | 
						
							| 84 | 83 | oveq2d | ⊢ ( 𝑏  =  𝑥  →  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) ) ) | 
						
							| 85 | 84 | eqeq1d | ⊢ ( 𝑏  =  𝑥  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 86 | 82 85 | anbi12d | ⊢ ( 𝑏  =  𝑥  →  ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ( 𝑦  ≤  𝑥  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 87 |  | equequ1 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑏  =  𝑐  ↔  𝑥  =  𝑐 ) ) | 
						
							| 88 | 87 | imbi2d | ⊢ ( 𝑏  =  𝑥  →  ( ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 )  ↔  ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) ) | 
						
							| 89 | 88 | ralbidv | ⊢ ( 𝑏  =  𝑥  →  ( ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 )  ↔  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) ) | 
						
							| 90 | 86 89 | anbi12d | ⊢ ( 𝑏  =  𝑥  →  ( ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) )  ↔  ( ( 𝑦  ≤  𝑥  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) ) ) | 
						
							| 91 | 90 | adantl | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  ∧  𝑏  =  𝑥 )  →  ( ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) )  ↔  ( ( 𝑦  ≤  𝑥  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) ) ) | 
						
							| 92 |  | ltnle | ⊢ ( ( 𝑦  ∈  ℝ  ∧  𝑥  ∈  ℝ )  →  ( 𝑦  <  𝑥  ↔  ¬  𝑥  ≤  𝑦 ) ) | 
						
							| 93 | 28 32 92 | syl2anr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑦  <  𝑥  ↔  ¬  𝑥  ≤  𝑦 ) ) | 
						
							| 94 | 28 | ad2antlr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑦  <  𝑥 )  →  𝑦  ∈  ℝ ) | 
						
							| 95 | 32 | ad2antrr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑦  <  𝑥 )  →  𝑥  ∈  ℝ ) | 
						
							| 96 |  | simpr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑦  <  𝑥 )  →  𝑦  <  𝑥 ) | 
						
							| 97 | 94 95 96 | ltled | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑦  <  𝑥 )  →  𝑦  ≤  𝑥 ) | 
						
							| 98 | 97 | ex | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑦  <  𝑥  →  𝑦  ≤  𝑥 ) ) | 
						
							| 99 | 93 98 | sylbird | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( ¬  𝑥  ≤  𝑦  →  𝑦  ≤  𝑥 ) ) | 
						
							| 100 | 99 | imp | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  𝑦  ≤  𝑥 ) | 
						
							| 101 | 29 | recnd | ⊢ ( 𝑦  ∈  ℕ  →  ( 𝑦 ↑ 2 )  ∈  ℂ ) | 
						
							| 102 | 101 | adantl | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℂ ) | 
						
							| 103 | 33 | recnd | ⊢ ( 𝑥  ∈  ℕ  →  ( 𝑥 ↑ 2 )  ∈  ℂ ) | 
						
							| 104 | 103 | adantr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℂ ) | 
						
							| 105 | 102 104 | addcomd | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 106 | 105 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) | 
						
							| 107 | 34 | recnd | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℂ ) | 
						
							| 108 | 107 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℂ ) | 
						
							| 109 | 30 | recnd | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℂ ) | 
						
							| 110 | 109 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℂ ) | 
						
							| 111 | 108 110 | addcomd | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) ) ) | 
						
							| 112 | 111 | eqeq2d | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) ) ) ) | 
						
							| 113 | 26 | adantl | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( 𝑐 ↑ 2 )  ∈  ℝ ) | 
						
							| 114 | 33 | ad2antrr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( 𝑥 ↑ 2 )  ∈  ℝ ) | 
						
							| 115 | 29 | ad2antlr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( 𝑦 ↑ 2 )  ∈  ℝ ) | 
						
							| 116 |  | readdcan | ⊢ ( ( ( 𝑐 ↑ 2 )  ∈  ℝ  ∧  ( 𝑥 ↑ 2 )  ∈  ℝ  ∧  ( 𝑦 ↑ 2 )  ∈  ℝ )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  ↔  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) ) | 
						
							| 117 | 113 114 115 116 | syl3anc | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  ↔  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) ) | 
						
							| 118 | 112 117 | bitrd | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) ) | 
						
							| 119 | 25 | ad2antlr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  𝑐  ∈  ℝ ) | 
						
							| 120 | 32 | adantr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  𝑥  ∈  ℝ ) | 
						
							| 121 | 120 | ad2antrr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  𝑥  ∈  ℝ ) | 
						
							| 122 | 44 | ad2antlr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  0  ≤  𝑐 ) | 
						
							| 123 |  | nnnn0 | ⊢ ( 𝑥  ∈  ℕ  →  𝑥  ∈  ℕ0 ) | 
						
							| 124 | 123 | nn0ge0d | ⊢ ( 𝑥  ∈  ℕ  →  0  ≤  𝑥 ) | 
						
							| 125 | 124 | adantr | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  0  ≤  𝑥 ) | 
						
							| 126 | 125 | ad2antrr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  0  ≤  𝑥 ) | 
						
							| 127 |  | simpr | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) ) | 
						
							| 128 | 119 121 122 126 127 | sq11d | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  𝑐  =  𝑥 ) | 
						
							| 129 | 128 | eqcomd | ⊢ ( ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  ∧  ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 ) )  →  𝑥  =  𝑐 ) | 
						
							| 130 | 129 | ex | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( 𝑐 ↑ 2 )  =  ( 𝑥 ↑ 2 )  →  𝑥  =  𝑐 ) ) | 
						
							| 131 | 118 130 | sylbid | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  𝑥  =  𝑐 ) ) | 
						
							| 132 | 131 | adantld | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑐  ∈  ℕ )  →  ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) | 
						
							| 133 | 132 | ralrimiva | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) | 
						
							| 134 | 133 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) | 
						
							| 135 | 100 106 134 | jca31 | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  ( ( 𝑦  ≤  𝑥  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑥 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑥  =  𝑐 ) ) ) | 
						
							| 136 | 81 91 135 | rspcedvd | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  ∃ 𝑏  ∈  ℕ ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) ) ) | 
						
							| 137 |  | breq2 | ⊢ ( 𝑏  =  𝑐  →  ( 𝑦  ≤  𝑏  ↔  𝑦  ≤  𝑐 ) ) | 
						
							| 138 | 56 | oveq2d | ⊢ ( 𝑏  =  𝑐  →  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) ) ) | 
						
							| 139 | 138 | eqeq1d | ⊢ ( 𝑏  =  𝑐  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  ↔  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 140 | 137 139 | anbi12d | ⊢ ( 𝑏  =  𝑐  →  ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 141 | 140 | reu8 | ⊢ ( ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ↔  ∃ 𝑏  ∈  ℕ ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  ∧  ∀ 𝑐  ∈  ℕ ( ( 𝑦  ≤  𝑐  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑐 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  𝑏  =  𝑐 ) ) ) | 
						
							| 142 | 136 141 | sylibr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  ¬  𝑥  ≤  𝑦 )  →  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 143 | 142 | ex | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( ¬  𝑥  ≤  𝑦  →  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 144 | 143 | adantr | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  ( ¬  𝑥  ≤  𝑦  →  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 145 | 144 | impcom | ⊢ ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 146 |  | eqeq2 | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃  ↔  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) | 
						
							| 147 | 146 | anbi2d | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 148 | 147 | reubidv | ⊢ ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 149 | 148 | adantl | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 150 | 149 | adantl | ⊢ ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) ) ) | 
						
							| 151 | 145 150 | mpbird | ⊢ ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃! 𝑏  ∈  ℕ ( 𝑦  ≤  𝑏  ∧  ( ( 𝑦 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 152 | 73 80 151 | rspcedvd | ⊢ ( ( ¬  𝑥  ≤  𝑦  ∧  ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 153 | 71 152 | pm2.61ian | ⊢ ( ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  ∧  𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 154 | 153 | ex | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ )  →  ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 155 | 154 | adantl | ⊢ ( ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  ∧  ( 𝑥  ∈  ℕ  ∧  𝑦  ∈  ℕ ) )  →  ( 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 156 | 155 | rexlimdvva | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ( ∃ 𝑥  ∈  ℕ ∃ 𝑦  ∈  ℕ 𝑃  =  ( ( 𝑥 ↑ 2 )  +  ( 𝑦 ↑ 2 ) )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 157 | 1 156 | mpd | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 158 |  | reurex | ⊢ ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 159 | 158 | a1i | ⊢ ( ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  ∧  𝑎  ∈  ℕ )  →  ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 160 | 159 | ralrimiva | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∀ 𝑎  ∈  ℕ ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 161 |  | 2sqmo | ⊢ ( 𝑃  ∈  ℙ  →  ∃* 𝑎  ∈  ℕ0 ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 162 |  | nnssnn0 | ⊢ ℕ  ⊆  ℕ0 | 
						
							| 163 |  | nfcv | ⊢ Ⅎ 𝑎 ℕ | 
						
							| 164 |  | nfcv | ⊢ Ⅎ 𝑎 ℕ0 | 
						
							| 165 | 163 164 | ssrmof | ⊢ ( ℕ  ⊆  ℕ0  →  ( ∃* 𝑎  ∈  ℕ0 ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 166 | 162 165 | ax-mp | ⊢ ( ∃* 𝑎  ∈  ℕ0 ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 167 |  | ssrexv | ⊢ ( ℕ  ⊆  ℕ0  →  ( ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 168 | 162 167 | ax-mp | ⊢ ( ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 169 | 168 | rmoimi | ⊢ ( ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ0 ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 170 | 161 166 169 | 3syl | ⊢ ( 𝑃  ∈  ℙ  →  ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 171 | 170 | adantr | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 172 |  | rmoim | ⊢ ( ∀ 𝑎  ∈  ℕ ( ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) )  →  ( ∃* 𝑎  ∈  ℕ ∃ 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  →  ∃* 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 173 | 160 171 172 | sylc | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∃* 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) | 
						
							| 174 |  | reu5 | ⊢ ( ∃! 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ↔  ( ∃ 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 )  ∧  ∃* 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) ) | 
						
							| 175 | 157 173 174 | sylanbrc | ⊢ ( ( 𝑃  ∈  ℙ  ∧  ( 𝑃  mod  4 )  =  1 )  →  ∃! 𝑎  ∈  ℕ ∃! 𝑏  ∈  ℕ ( 𝑎  ≤  𝑏  ∧  ( ( 𝑎 ↑ 2 )  +  ( 𝑏 ↑ 2 ) )  =  𝑃 ) ) |