| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ftc1.g | ⊢ 𝐺  =  ( 𝑥  ∈  ( 𝐴 [,] 𝐵 )  ↦  ∫ ( 𝐴 (,) 𝑥 ) ( 𝐹 ‘ 𝑡 )  d 𝑡 ) | 
						
							| 2 |  | ftc1.a | ⊢ ( 𝜑  →  𝐴  ∈  ℝ ) | 
						
							| 3 |  | ftc1.b | ⊢ ( 𝜑  →  𝐵  ∈  ℝ ) | 
						
							| 4 |  | ftc1.le | ⊢ ( 𝜑  →  𝐴  ≤  𝐵 ) | 
						
							| 5 |  | ftc1.s | ⊢ ( 𝜑  →  ( 𝐴 (,) 𝐵 )  ⊆  𝐷 ) | 
						
							| 6 |  | ftc1.d | ⊢ ( 𝜑  →  𝐷  ⊆  ℝ ) | 
						
							| 7 |  | ftc1.i | ⊢ ( 𝜑  →  𝐹  ∈  𝐿1 ) | 
						
							| 8 |  | ftc1.c | ⊢ ( 𝜑  →  𝐶  ∈  ( 𝐴 (,) 𝐵 ) ) | 
						
							| 9 |  | ftc1.f | ⊢ ( 𝜑  →  𝐹  ∈  ( ( 𝐾  CnP  𝐿 ) ‘ 𝐶 ) ) | 
						
							| 10 |  | ftc1.j | ⊢ 𝐽  =  ( 𝐿  ↾t  ℝ ) | 
						
							| 11 |  | ftc1.k | ⊢ 𝐾  =  ( 𝐿  ↾t  𝐷 ) | 
						
							| 12 |  | ftc1.l | ⊢ 𝐿  =  ( TopOpen ‘ ℂfld ) | 
						
							| 13 | 12 | cnfldtopon | ⊢ 𝐿  ∈  ( TopOn ‘ ℂ ) | 
						
							| 14 |  | ax-resscn | ⊢ ℝ  ⊆  ℂ | 
						
							| 15 | 6 14 | sstrdi | ⊢ ( 𝜑  →  𝐷  ⊆  ℂ ) | 
						
							| 16 |  | resttopon | ⊢ ( ( 𝐿  ∈  ( TopOn ‘ ℂ )  ∧  𝐷  ⊆  ℂ )  →  ( 𝐿  ↾t  𝐷 )  ∈  ( TopOn ‘ 𝐷 ) ) | 
						
							| 17 | 13 15 16 | sylancr | ⊢ ( 𝜑  →  ( 𝐿  ↾t  𝐷 )  ∈  ( TopOn ‘ 𝐷 ) ) | 
						
							| 18 | 11 17 | eqeltrid | ⊢ ( 𝜑  →  𝐾  ∈  ( TopOn ‘ 𝐷 ) ) | 
						
							| 19 | 13 | a1i | ⊢ ( 𝜑  →  𝐿  ∈  ( TopOn ‘ ℂ ) ) | 
						
							| 20 |  | cnpf2 | ⊢ ( ( 𝐾  ∈  ( TopOn ‘ 𝐷 )  ∧  𝐿  ∈  ( TopOn ‘ ℂ )  ∧  𝐹  ∈  ( ( 𝐾  CnP  𝐿 ) ‘ 𝐶 ) )  →  𝐹 : 𝐷 ⟶ ℂ ) | 
						
							| 21 | 18 19 9 20 | syl3anc | ⊢ ( 𝜑  →  𝐹 : 𝐷 ⟶ ℂ ) |