| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fourierdlem28.1 | ⊢ ( 𝜑  →  𝐹 : ℝ ⟶ ℝ ) | 
						
							| 2 |  | fourierdlem28.x | ⊢ ( 𝜑  →  𝑋  ∈  ℝ ) | 
						
							| 3 |  | fourierdlem28.a | ⊢ ( 𝜑  →  𝐴  ∈  ℝ ) | 
						
							| 4 |  | fourierdlem28.3b | ⊢ ( 𝜑  →  𝐵  ∈  ℝ ) | 
						
							| 5 |  | fourierdlem28.d | ⊢ 𝐷  =  ( ℝ  D  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) ) | 
						
							| 6 |  | fourierdlem28.df | ⊢ ( 𝜑  →  𝐷 : ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ⟶ ℝ ) | 
						
							| 7 |  | reelprrecn | ⊢ ℝ  ∈  { ℝ ,  ℂ } | 
						
							| 8 | 7 | a1i | ⊢ ( 𝜑  →  ℝ  ∈  { ℝ ,  ℂ } ) | 
						
							| 9 | 2 3 | readdcld | ⊢ ( 𝜑  →  ( 𝑋  +  𝐴 )  ∈  ℝ ) | 
						
							| 10 | 9 | rexrd | ⊢ ( 𝜑  →  ( 𝑋  +  𝐴 )  ∈  ℝ* ) | 
						
							| 11 | 10 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝐴 )  ∈  ℝ* ) | 
						
							| 12 | 2 4 | readdcld | ⊢ ( 𝜑  →  ( 𝑋  +  𝐵 )  ∈  ℝ ) | 
						
							| 13 | 12 | rexrd | ⊢ ( 𝜑  →  ( 𝑋  +  𝐵 )  ∈  ℝ* ) | 
						
							| 14 | 13 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝐵 )  ∈  ℝ* ) | 
						
							| 15 | 2 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑋  ∈  ℝ ) | 
						
							| 16 |  | elioore | ⊢ ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  →  𝑠  ∈  ℝ ) | 
						
							| 17 | 16 | adantl | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑠  ∈  ℝ ) | 
						
							| 18 | 15 17 | readdcld | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝑠 )  ∈  ℝ ) | 
						
							| 19 | 3 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐴  ∈  ℝ ) | 
						
							| 20 | 19 | rexrd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐴  ∈  ℝ* ) | 
						
							| 21 | 4 | rexrd | ⊢ ( 𝜑  →  𝐵  ∈  ℝ* ) | 
						
							| 22 | 21 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐵  ∈  ℝ* ) | 
						
							| 23 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑠  ∈  ( 𝐴 (,) 𝐵 ) ) | 
						
							| 24 |  | ioogtlb | ⊢ ( ( 𝐴  ∈  ℝ*  ∧  𝐵  ∈  ℝ*  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐴  <  𝑠 ) | 
						
							| 25 | 20 22 23 24 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐴  <  𝑠 ) | 
						
							| 26 | 19 17 15 25 | ltadd2dd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝐴 )  <  ( 𝑋  +  𝑠 ) ) | 
						
							| 27 | 4 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐵  ∈  ℝ ) | 
						
							| 28 |  | iooltub | ⊢ ( ( 𝐴  ∈  ℝ*  ∧  𝐵  ∈  ℝ*  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑠  <  𝐵 ) | 
						
							| 29 | 20 22 23 28 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑠  <  𝐵 ) | 
						
							| 30 | 17 27 15 29 | ltadd2dd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝑠 )  <  ( 𝑋  +  𝐵 ) ) | 
						
							| 31 | 11 14 18 26 30 | eliood | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝑋  +  𝑠 )  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) | 
						
							| 32 |  | 1red | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  1  ∈  ℝ ) | 
						
							| 33 | 1 | adantr | ⊢ ( ( 𝜑  ∧  𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  →  𝐹 : ℝ ⟶ ℝ ) | 
						
							| 34 |  | elioore | ⊢ ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  →  𝑦  ∈  ℝ ) | 
						
							| 35 | 34 | adantl | ⊢ ( ( 𝜑  ∧  𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  →  𝑦  ∈  ℝ ) | 
						
							| 36 | 33 35 | ffvelcdmd | ⊢ ( ( 𝜑  ∧  𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  →  ( 𝐹 ‘ 𝑦 )  ∈  ℝ ) | 
						
							| 37 | 36 | recnd | ⊢ ( ( 𝜑  ∧  𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  →  ( 𝐹 ‘ 𝑦 )  ∈  ℂ ) | 
						
							| 38 | 6 | ffvelcdmda | ⊢ ( ( 𝜑  ∧  𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  →  ( 𝐷 ‘ 𝑦 )  ∈  ℝ ) | 
						
							| 39 | 15 | recnd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑋  ∈  ℂ ) | 
						
							| 40 |  | 0red | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  0  ∈  ℝ ) | 
						
							| 41 |  | iooretop | ⊢ ( 𝐴 (,) 𝐵 )  ∈  ( topGen ‘ ran  (,) ) | 
						
							| 42 |  | tgioo4 | ⊢ ( topGen ‘ ran  (,) )  =  ( ( TopOpen ‘ ℂfld )  ↾t  ℝ ) | 
						
							| 43 | 41 42 | eleqtri | ⊢ ( 𝐴 (,) 𝐵 )  ∈  ( ( TopOpen ‘ ℂfld )  ↾t  ℝ ) | 
						
							| 44 | 43 | a1i | ⊢ ( 𝜑  →  ( 𝐴 (,) 𝐵 )  ∈  ( ( TopOpen ‘ ℂfld )  ↾t  ℝ ) ) | 
						
							| 45 | 2 | recnd | ⊢ ( 𝜑  →  𝑋  ∈  ℂ ) | 
						
							| 46 | 8 44 45 | dvmptconst | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  𝑋 ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  0 ) ) | 
						
							| 47 | 17 | recnd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝑠  ∈  ℂ ) | 
						
							| 48 | 8 44 | dvmptidg | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  𝑠 ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  1 ) ) | 
						
							| 49 | 8 39 40 46 47 32 48 | dvmptadd | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝑋  +  𝑠 ) ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 0  +  1 ) ) ) | 
						
							| 50 |  | 0p1e1 | ⊢ ( 0  +  1 )  =  1 | 
						
							| 51 | 50 | a1i | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 0  +  1 )  =  1 ) | 
						
							| 52 | 51 | mpteq2dva | ⊢ ( 𝜑  →  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 0  +  1 ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  1 ) ) | 
						
							| 53 | 49 52 | eqtrd | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝑋  +  𝑠 ) ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  1 ) ) | 
						
							| 54 | 1 | feqmptd | ⊢ ( 𝜑  →  𝐹  =  ( 𝑦  ∈  ℝ  ↦  ( 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 55 | 54 | reseq1d | ⊢ ( 𝜑  →  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  =  ( ( 𝑦  ∈  ℝ  ↦  ( 𝐹 ‘ 𝑦 ) )  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) ) | 
						
							| 56 |  | ioossre | ⊢ ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ⊆  ℝ | 
						
							| 57 | 56 | a1i | ⊢ ( 𝜑  →  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ⊆  ℝ ) | 
						
							| 58 | 57 | resmptd | ⊢ ( 𝜑  →  ( ( 𝑦  ∈  ℝ  ↦  ( 𝐹 ‘ 𝑦 ) )  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) )  =  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 59 | 55 58 | eqtr2d | ⊢ ( 𝜑  →  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐹 ‘ 𝑦 ) )  =  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) ) | 
						
							| 60 | 59 | oveq2d | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐹 ‘ 𝑦 ) ) )  =  ( ℝ  D  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) ) ) | 
						
							| 61 | 5 | eqcomi | ⊢ ( ℝ  D  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) )  =  𝐷 | 
						
							| 62 | 61 | a1i | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝐹  ↾  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ) )  =  𝐷 ) | 
						
							| 63 | 6 | feqmptd | ⊢ ( 𝜑  →  𝐷  =  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐷 ‘ 𝑦 ) ) ) | 
						
							| 64 | 60 62 63 | 3eqtrd | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐹 ‘ 𝑦 ) ) )  =  ( 𝑦  ∈  ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) )  ↦  ( 𝐷 ‘ 𝑦 ) ) ) | 
						
							| 65 |  | fveq2 | ⊢ ( 𝑦  =  ( 𝑋  +  𝑠 )  →  ( 𝐹 ‘ 𝑦 )  =  ( 𝐹 ‘ ( 𝑋  +  𝑠 ) ) ) | 
						
							| 66 |  | fveq2 | ⊢ ( 𝑦  =  ( 𝑋  +  𝑠 )  →  ( 𝐷 ‘ 𝑦 )  =  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) ) ) | 
						
							| 67 | 8 8 31 32 37 38 53 64 65 66 | dvmptco | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝐹 ‘ ( 𝑋  +  𝑠 ) ) ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( ( 𝐷 ‘ ( 𝑋  +  𝑠 ) )  ·  1 ) ) ) | 
						
							| 68 | 6 | adantr | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  𝐷 : ( ( 𝑋  +  𝐴 ) (,) ( 𝑋  +  𝐵 ) ) ⟶ ℝ ) | 
						
							| 69 | 68 31 | ffvelcdmd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) )  ∈  ℝ ) | 
						
							| 70 | 69 | recnd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) )  ∈  ℂ ) | 
						
							| 71 | 70 | mulridd | ⊢ ( ( 𝜑  ∧  𝑠  ∈  ( 𝐴 (,) 𝐵 ) )  →  ( ( 𝐷 ‘ ( 𝑋  +  𝑠 ) )  ·  1 )  =  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) ) ) | 
						
							| 72 | 71 | mpteq2dva | ⊢ ( 𝜑  →  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( ( 𝐷 ‘ ( 𝑋  +  𝑠 ) )  ·  1 ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) ) ) ) | 
						
							| 73 | 67 72 | eqtrd | ⊢ ( 𝜑  →  ( ℝ  D  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝐹 ‘ ( 𝑋  +  𝑠 ) ) ) )  =  ( 𝑠  ∈  ( 𝐴 (,) 𝐵 )  ↦  ( 𝐷 ‘ ( 𝑋  +  𝑠 ) ) ) ) |