| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opsqrlem2.1 | ⊢ 𝑇  ∈  HrmOp | 
						
							| 2 |  | opsqrlem2.2 | ⊢ 𝑆  =  ( 𝑥  ∈  HrmOp ,  𝑦  ∈  HrmOp  ↦  ( 𝑥  +op  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑥  ∘  𝑥 ) ) ) ) ) | 
						
							| 3 |  | opsqrlem2.3 | ⊢ 𝐹  =  seq 1 ( 𝑆 ,  ( ℕ  ×  {  0hop  } ) ) | 
						
							| 4 |  | nnuz | ⊢ ℕ  =  ( ℤ≥ ‘ 1 ) | 
						
							| 5 |  | 1zzd | ⊢ ( ⊤  →  1  ∈  ℤ ) | 
						
							| 6 |  | 0hmop | ⊢  0hop   ∈  HrmOp | 
						
							| 7 | 6 | elexi | ⊢  0hop   ∈  V | 
						
							| 8 | 7 | fvconst2 | ⊢ ( 𝑧  ∈  ℕ  →  ( ( ℕ  ×  {  0hop  } ) ‘ 𝑧 )  =   0hop  ) | 
						
							| 9 | 8 6 | eqeltrdi | ⊢ ( 𝑧  ∈  ℕ  →  ( ( ℕ  ×  {  0hop  } ) ‘ 𝑧 )  ∈  HrmOp ) | 
						
							| 10 | 9 | adantl | ⊢ ( ( ⊤  ∧  𝑧  ∈  ℕ )  →  ( ( ℕ  ×  {  0hop  } ) ‘ 𝑧 )  ∈  HrmOp ) | 
						
							| 11 | 1 2 3 | opsqrlem3 | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑧 𝑆 𝑤 )  =  ( 𝑧  +op  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) ) ) ) | 
						
							| 12 |  | halfre | ⊢ ( 1  /  2 )  ∈  ℝ | 
						
							| 13 |  | simpl | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  𝑧  ∈  HrmOp ) | 
						
							| 14 |  | eqidd | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑧  ∘  𝑧 )  =  ( 𝑧  ∘  𝑧 ) ) | 
						
							| 15 |  | hmopco | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑧  ∈  HrmOp  ∧  ( 𝑧  ∘  𝑧 )  =  ( 𝑧  ∘  𝑧 ) )  →  ( 𝑧  ∘  𝑧 )  ∈  HrmOp ) | 
						
							| 16 | 13 13 14 15 | syl3anc | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑧  ∘  𝑧 )  ∈  HrmOp ) | 
						
							| 17 |  | hmopd | ⊢ ( ( 𝑇  ∈  HrmOp  ∧  ( 𝑧  ∘  𝑧 )  ∈  HrmOp )  →  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) )  ∈  HrmOp ) | 
						
							| 18 | 1 16 17 | sylancr | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) )  ∈  HrmOp ) | 
						
							| 19 |  | hmopm | ⊢ ( ( ( 1  /  2 )  ∈  ℝ  ∧  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) )  ∈  HrmOp )  →  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) )  ∈  HrmOp ) | 
						
							| 20 | 12 18 19 | sylancr | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) )  ∈  HrmOp ) | 
						
							| 21 |  | hmops | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) )  ∈  HrmOp )  →  ( 𝑧  +op  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) ) )  ∈  HrmOp ) | 
						
							| 22 | 20 21 | syldan | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑧  +op  ( ( 1  /  2 )  ·op  ( 𝑇  −op  ( 𝑧  ∘  𝑧 ) ) ) )  ∈  HrmOp ) | 
						
							| 23 | 11 22 | eqeltrd | ⊢ ( ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp )  →  ( 𝑧 𝑆 𝑤 )  ∈  HrmOp ) | 
						
							| 24 | 23 | adantl | ⊢ ( ( ⊤  ∧  ( 𝑧  ∈  HrmOp  ∧  𝑤  ∈  HrmOp ) )  →  ( 𝑧 𝑆 𝑤 )  ∈  HrmOp ) | 
						
							| 25 | 4 5 10 24 | seqf | ⊢ ( ⊤  →  seq 1 ( 𝑆 ,  ( ℕ  ×  {  0hop  } ) ) : ℕ ⟶ HrmOp ) | 
						
							| 26 | 25 | mptru | ⊢ seq 1 ( 𝑆 ,  ( ℕ  ×  {  0hop  } ) ) : ℕ ⟶ HrmOp | 
						
							| 27 | 3 | feq1i | ⊢ ( 𝐹 : ℕ ⟶ HrmOp  ↔  seq 1 ( 𝑆 ,  ( ℕ  ×  {  0hop  } ) ) : ℕ ⟶ HrmOp ) | 
						
							| 28 | 26 27 | mpbir | ⊢ 𝐹 : ℕ ⟶ HrmOp |