| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ovolicc.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℝ ) | 
						
							| 2 |  | ovolicc.2 | ⊢ ( 𝜑  →  𝐵  ∈  ℝ ) | 
						
							| 3 |  | ovolicc.3 | ⊢ ( 𝜑  →  𝐴  ≤  𝐵 ) | 
						
							| 4 |  | ovolicc2.m | ⊢ 𝑀  =  { 𝑦  ∈  ℝ*  ∣  ∃ 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  ∧  𝑦  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) } | 
						
							| 5 | 4 | elovolm | ⊢ ( 𝑧  ∈  𝑀  ↔  ∃ 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  ∧  𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 6 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) | 
						
							| 7 |  | unieq | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  ∪  𝑢  =  ∪  ran  ( (,)  ∘  𝑓 ) ) | 
						
							| 8 | 7 | sseq2d | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  ↔  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) ) | 
						
							| 9 |  | pweq | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  𝒫  𝑢  =  𝒫  ran  ( (,)  ∘  𝑓 ) ) | 
						
							| 10 | 9 | ineq1d | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  ( 𝒫  𝑢  ∩  Fin )  =  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ) | 
						
							| 11 | 10 | rexeqdv | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  ( ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣  ↔  ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) | 
						
							| 12 | 8 11 | imbi12d | ⊢ ( 𝑢  =  ran  ( (,)  ∘  𝑓 )  →  ( ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  →  ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ↔  ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  →  ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) ) | 
						
							| 13 |  | eqid | ⊢ ( topGen ‘ ran  (,) )  =  ( topGen ‘ ran  (,) ) | 
						
							| 14 |  | eqid | ⊢ ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) )  =  ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) ) | 
						
							| 15 | 13 14 | icccmp | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ )  →  ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) )  ∈  Comp ) | 
						
							| 16 | 1 2 15 | syl2anc | ⊢ ( 𝜑  →  ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) )  ∈  Comp ) | 
						
							| 17 |  | retop | ⊢ ( topGen ‘ ran  (,) )  ∈  Top | 
						
							| 18 |  | iccssre | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ )  →  ( 𝐴 [,] 𝐵 )  ⊆  ℝ ) | 
						
							| 19 | 1 2 18 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴 [,] 𝐵 )  ⊆  ℝ ) | 
						
							| 20 |  | uniretop | ⊢ ℝ  =  ∪  ( topGen ‘ ran  (,) ) | 
						
							| 21 | 20 | cmpsub | ⊢ ( ( ( topGen ‘ ran  (,) )  ∈  Top  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ℝ )  →  ( ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) )  ∈  Comp  ↔  ∀ 𝑢  ∈  𝒫  ( topGen ‘ ran  (,) ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  →  ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) ) | 
						
							| 22 | 17 19 21 | sylancr | ⊢ ( 𝜑  →  ( ( ( topGen ‘ ran  (,) )  ↾t  ( 𝐴 [,] 𝐵 ) )  ∈  Comp  ↔  ∀ 𝑢  ∈  𝒫  ( topGen ‘ ran  (,) ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  →  ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) ) | 
						
							| 23 | 16 22 | mpbid | ⊢ ( 𝜑  →  ∀ 𝑢  ∈  𝒫  ( topGen ‘ ran  (,) ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  →  ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) | 
						
							| 24 | 23 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ∀ 𝑢  ∈  𝒫  ( topGen ‘ ran  (,) ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑢  →  ∃ 𝑣  ∈  ( 𝒫  𝑢  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) | 
						
							| 25 |  | ioof | ⊢ (,) : ( ℝ*  ×  ℝ* ) ⟶ 𝒫  ℝ | 
						
							| 26 |  | ffn | ⊢ ( (,) : ( ℝ*  ×  ℝ* ) ⟶ 𝒫  ℝ  →  (,)  Fn  ( ℝ*  ×  ℝ* ) ) | 
						
							| 27 | 25 26 | ax-mp | ⊢ (,)  Fn  ( ℝ*  ×  ℝ* ) | 
						
							| 28 |  | dffn3 | ⊢ ( (,)  Fn  ( ℝ*  ×  ℝ* )  ↔  (,) : ( ℝ*  ×  ℝ* ) ⟶ ran  (,) ) | 
						
							| 29 | 27 28 | mpbi | ⊢ (,) : ( ℝ*  ×  ℝ* ) ⟶ ran  (,) | 
						
							| 30 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) ) | 
						
							| 31 |  | elovolmlem | ⊢ ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ↔  𝑓 : ℕ ⟶ (  ≤   ∩  ( ℝ  ×  ℝ ) ) ) | 
						
							| 32 | 30 31 | sylib | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  𝑓 : ℕ ⟶ (  ≤   ∩  ( ℝ  ×  ℝ ) ) ) | 
						
							| 33 |  | inss2 | ⊢ (  ≤   ∩  ( ℝ  ×  ℝ ) )  ⊆  ( ℝ  ×  ℝ ) | 
						
							| 34 |  | rexpssxrxp | ⊢ ( ℝ  ×  ℝ )  ⊆  ( ℝ*  ×  ℝ* ) | 
						
							| 35 | 33 34 | sstri | ⊢ (  ≤   ∩  ( ℝ  ×  ℝ ) )  ⊆  ( ℝ*  ×  ℝ* ) | 
						
							| 36 |  | fss | ⊢ ( ( 𝑓 : ℕ ⟶ (  ≤   ∩  ( ℝ  ×  ℝ ) )  ∧  (  ≤   ∩  ( ℝ  ×  ℝ ) )  ⊆  ( ℝ*  ×  ℝ* ) )  →  𝑓 : ℕ ⟶ ( ℝ*  ×  ℝ* ) ) | 
						
							| 37 | 32 35 36 | sylancl | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  𝑓 : ℕ ⟶ ( ℝ*  ×  ℝ* ) ) | 
						
							| 38 |  | fco | ⊢ ( ( (,) : ( ℝ*  ×  ℝ* ) ⟶ ran  (,)  ∧  𝑓 : ℕ ⟶ ( ℝ*  ×  ℝ* ) )  →  ( (,)  ∘  𝑓 ) : ℕ ⟶ ran  (,) ) | 
						
							| 39 | 29 37 38 | sylancr | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  ( (,)  ∘  𝑓 ) : ℕ ⟶ ran  (,) ) | 
						
							| 40 | 39 | adantrr | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( (,)  ∘  𝑓 ) : ℕ ⟶ ran  (,) ) | 
						
							| 41 | 40 | frnd | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ran  ( (,)  ∘  𝑓 )  ⊆  ran  (,) ) | 
						
							| 42 |  | retopbas | ⊢ ran  (,)  ∈  TopBases | 
						
							| 43 |  | bastg | ⊢ ( ran  (,)  ∈  TopBases  →  ran  (,)  ⊆  ( topGen ‘ ran  (,) ) ) | 
						
							| 44 | 42 43 | ax-mp | ⊢ ran  (,)  ⊆  ( topGen ‘ ran  (,) ) | 
						
							| 45 | 41 44 | sstrdi | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ran  ( (,)  ∘  𝑓 )  ⊆  ( topGen ‘ ran  (,) ) ) | 
						
							| 46 |  | fvex | ⊢ ( topGen ‘ ran  (,) )  ∈  V | 
						
							| 47 | 46 | elpw2 | ⊢ ( ran  ( (,)  ∘  𝑓 )  ∈  𝒫  ( topGen ‘ ran  (,) )  ↔  ran  ( (,)  ∘  𝑓 )  ⊆  ( topGen ‘ ran  (,) ) ) | 
						
							| 48 | 45 47 | sylibr | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ran  ( (,)  ∘  𝑓 )  ∈  𝒫  ( topGen ‘ ran  (,) ) ) | 
						
							| 49 | 12 24 48 | rspcdva | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  →  ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) ) | 
						
							| 50 | 6 49 | mpd | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) | 
						
							| 51 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ) | 
						
							| 52 |  | elin | ⊢ ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ↔  ( 𝑣  ∈  𝒫  ran  ( (,)  ∘  𝑓 )  ∧  𝑣  ∈  Fin ) ) | 
						
							| 53 | 51 52 | sylib | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( 𝑣  ∈  𝒫  ran  ( (,)  ∘  𝑓 )  ∧  𝑣  ∈  Fin ) ) | 
						
							| 54 | 53 | simprd | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  𝑣  ∈  Fin ) | 
						
							| 55 | 53 | simpld | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  𝑣  ∈  𝒫  ran  ( (,)  ∘  𝑓 ) ) | 
						
							| 56 | 55 | elpwid | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  𝑣  ⊆  ran  ( (,)  ∘  𝑓 ) ) | 
						
							| 57 | 56 | sseld | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( 𝑡  ∈  𝑣  →  𝑡  ∈  ran  ( (,)  ∘  𝑓 ) ) ) | 
						
							| 58 | 39 | ffnd | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  ( (,)  ∘  𝑓 )  Fn  ℕ ) | 
						
							| 59 | 58 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( (,)  ∘  𝑓 )  Fn  ℕ ) | 
						
							| 60 |  | fvelrnb | ⊢ ( ( (,)  ∘  𝑓 )  Fn  ℕ  →  ( 𝑡  ∈  ran  ( (,)  ∘  𝑓 )  ↔  ∃ 𝑘  ∈  ℕ ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡 ) ) | 
						
							| 61 | 59 60 | syl | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( 𝑡  ∈  ran  ( (,)  ∘  𝑓 )  ↔  ∃ 𝑘  ∈  ℕ ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡 ) ) | 
						
							| 62 | 57 61 | sylibd | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( 𝑡  ∈  𝑣  →  ∃ 𝑘  ∈  ℕ ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡 ) ) | 
						
							| 63 | 62 | ralrimiv | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ∀ 𝑡  ∈  𝑣 ∃ 𝑘  ∈  ℕ ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡 ) | 
						
							| 64 |  | fveqeq2 | ⊢ ( 𝑘  =  ( 𝑔 ‘ 𝑡 )  →  ( ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡  ↔  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) | 
						
							| 65 | 64 | ac6sfi | ⊢ ( ( 𝑣  ∈  Fin  ∧  ∀ 𝑡  ∈  𝑣 ∃ 𝑘  ∈  ℕ ( ( (,)  ∘  𝑓 ) ‘ 𝑘 )  =  𝑡 )  →  ∃ 𝑔 ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) | 
						
							| 66 | 54 63 65 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ∃ 𝑔 ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) | 
						
							| 67 | 1 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝐴  ∈  ℝ ) | 
						
							| 68 | 2 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝐵  ∈  ℝ ) | 
						
							| 69 | 3 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝐴  ≤  𝐵 ) | 
						
							| 70 |  | eqid | ⊢ seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) )  =  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) | 
						
							| 71 | 32 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝑓 : ℕ ⟶ (  ≤   ∩  ( ℝ  ×  ℝ ) ) ) | 
						
							| 72 |  | simprll | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ) | 
						
							| 73 |  | simprlr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) | 
						
							| 74 |  | simprrl | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  𝑔 : 𝑣 ⟶ ℕ ) | 
						
							| 75 |  | simprrr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) | 
						
							| 76 |  | 2fveq3 | ⊢ ( 𝑡  =  𝑥  →  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑥 ) ) ) | 
						
							| 77 |  | id | ⊢ ( 𝑡  =  𝑥  →  𝑡  =  𝑥 ) | 
						
							| 78 | 76 77 | eqeq12d | ⊢ ( 𝑡  =  𝑥  →  ( ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡  ↔  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑥 ) )  =  𝑥 ) ) | 
						
							| 79 | 78 | rspccva | ⊢ ( ( ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡  ∧  𝑥  ∈  𝑣 )  →  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑥 ) )  =  𝑥 ) | 
						
							| 80 | 75 79 | sylan | ⊢ ( ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  ∧  𝑥  ∈  𝑣 )  →  ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑥 ) )  =  𝑥 ) | 
						
							| 81 |  | eqid | ⊢ { 𝑢  ∈  𝑣  ∣  ( 𝑢  ∩  ( 𝐴 [,] 𝐵 ) )  ≠  ∅ }  =  { 𝑢  ∈  𝑣  ∣  ( 𝑢  ∩  ( 𝐴 [,] 𝐵 ) )  ≠  ∅ } | 
						
							| 82 | 67 68 69 70 71 72 73 74 80 81 | ovolicc2lem5 | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 )  ∧  ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 ) ) )  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) | 
						
							| 83 | 82 | expr | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 )  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 84 | 83 | exlimdv | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( ∃ 𝑔 ( 𝑔 : 𝑣 ⟶ ℕ  ∧  ∀ 𝑡  ∈  𝑣 ( ( (,)  ∘  𝑓 ) ‘ ( 𝑔 ‘ 𝑡 ) )  =  𝑡 )  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 85 | 66 84 | mpd | ⊢ ( ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  ∧  ( 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣 ) )  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) | 
						
							| 86 | 85 | rexlimdvaa | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  ( ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 87 | 86 | adantrr | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( ∃ 𝑣  ∈  ( 𝒫  ran  ( (,)  ∘  𝑓 )  ∩  Fin ) ( 𝐴 [,] 𝐵 )  ⊆  ∪  𝑣  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 88 | 50 87 | mpd | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) | 
						
							| 89 |  | breq2 | ⊢ ( 𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  )  →  ( ( 𝐵  −  𝐴 )  ≤  𝑧  ↔  ( 𝐵  −  𝐴 )  ≤  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) ) ) | 
						
							| 90 | 88 89 | syl5ibrcom | ⊢ ( ( 𝜑  ∧  ( 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ )  ∧  ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 ) ) )  →  ( 𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  )  →  ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 91 | 90 | expr | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  →  ( 𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  )  →  ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) ) | 
						
							| 92 | 91 | impd | ⊢ ( ( 𝜑  ∧  𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) )  →  ( ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  ∧  𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) )  →  ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 93 | 92 | rexlimdva | ⊢ ( 𝜑  →  ( ∃ 𝑓  ∈  ( (  ≤   ∩  ( ℝ  ×  ℝ ) )  ↑m  ℕ ) ( ( 𝐴 [,] 𝐵 )  ⊆  ∪  ran  ( (,)  ∘  𝑓 )  ∧  𝑧  =  sup ( ran  seq 1 (  +  ,  ( ( abs  ∘   −  )  ∘  𝑓 ) ) ,  ℝ* ,   <  ) )  →  ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 94 | 5 93 | biimtrid | ⊢ ( 𝜑  →  ( 𝑧  ∈  𝑀  →  ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 95 | 94 | ralrimiv | ⊢ ( 𝜑  →  ∀ 𝑧  ∈  𝑀 ( 𝐵  −  𝐴 )  ≤  𝑧 ) | 
						
							| 96 | 4 | ssrab3 | ⊢ 𝑀  ⊆  ℝ* | 
						
							| 97 | 2 1 | resubcld | ⊢ ( 𝜑  →  ( 𝐵  −  𝐴 )  ∈  ℝ ) | 
						
							| 98 | 97 | rexrd | ⊢ ( 𝜑  →  ( 𝐵  −  𝐴 )  ∈  ℝ* ) | 
						
							| 99 |  | infxrgelb | ⊢ ( ( 𝑀  ⊆  ℝ*  ∧  ( 𝐵  −  𝐴 )  ∈  ℝ* )  →  ( ( 𝐵  −  𝐴 )  ≤  inf ( 𝑀 ,  ℝ* ,   <  )  ↔  ∀ 𝑧  ∈  𝑀 ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 100 | 96 98 99 | sylancr | ⊢ ( 𝜑  →  ( ( 𝐵  −  𝐴 )  ≤  inf ( 𝑀 ,  ℝ* ,   <  )  ↔  ∀ 𝑧  ∈  𝑀 ( 𝐵  −  𝐴 )  ≤  𝑧 ) ) | 
						
							| 101 | 95 100 | mpbird | ⊢ ( 𝜑  →  ( 𝐵  −  𝐴 )  ≤  inf ( 𝑀 ,  ℝ* ,   <  ) ) | 
						
							| 102 | 4 | ovolval | ⊢ ( ( 𝐴 [,] 𝐵 )  ⊆  ℝ  →  ( vol* ‘ ( 𝐴 [,] 𝐵 ) )  =  inf ( 𝑀 ,  ℝ* ,   <  ) ) | 
						
							| 103 | 19 102 | syl | ⊢ ( 𝜑  →  ( vol* ‘ ( 𝐴 [,] 𝐵 ) )  =  inf ( 𝑀 ,  ℝ* ,   <  ) ) | 
						
							| 104 | 101 103 | breqtrrd | ⊢ ( 𝜑  →  ( 𝐵  −  𝐴 )  ≤  ( vol* ‘ ( 𝐴 [,] 𝐵 ) ) ) |