| Step | Hyp | Ref | Expression | 
						
							| 1 |  | voliunlem.3 | ⊢ ( 𝜑  →  𝐹 : ℕ ⟶ dom  vol ) | 
						
							| 2 |  | voliunlem.5 | ⊢ ( 𝜑  →  Disj  𝑖  ∈  ℕ ( 𝐹 ‘ 𝑖 ) ) | 
						
							| 3 |  | voliunlem1.6 | ⊢ 𝐻  =  ( 𝑛  ∈  ℕ  ↦  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 4 |  | voliunlem1.7 | ⊢ ( 𝜑  →  𝐸  ⊆  ℝ ) | 
						
							| 5 |  | voliunlem1.8 | ⊢ ( 𝜑  →  ( vol* ‘ 𝐸 )  ∈  ℝ ) | 
						
							| 6 |  | difss | ⊢ ( 𝐸  ∖  ∪  ran  𝐹 )  ⊆  𝐸 | 
						
							| 7 | 5 | adantr | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ 𝐸 )  ∈  ℝ ) | 
						
							| 8 |  | ovolsscl | ⊢ ( ( ( 𝐸  ∖  ∪  ran  𝐹 )  ⊆  𝐸  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) )  ∈  ℝ ) | 
						
							| 9 | 6 4 7 8 | mp3an2ani | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) )  ∈  ℝ ) | 
						
							| 10 |  | difss | ⊢ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸 | 
						
							| 11 |  | ovolsscl | ⊢ ( ( ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 12 | 10 4 7 11 | mp3an2ani | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 13 |  | inss1 | ⊢ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸 | 
						
							| 14 |  | ovolsscl | ⊢ ( ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 15 | 13 4 7 14 | mp3an2ani | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 16 |  | elfznn | ⊢ ( 𝑛  ∈  ( 1 ... 𝑘 )  →  𝑛  ∈  ℕ ) | 
						
							| 17 | 1 | ffnd | ⊢ ( 𝜑  →  𝐹  Fn  ℕ ) | 
						
							| 18 |  | fnfvelrn | ⊢ ( ( 𝐹  Fn  ℕ  ∧  𝑛  ∈  ℕ )  →  ( 𝐹 ‘ 𝑛 )  ∈  ran  𝐹 ) | 
						
							| 19 | 17 18 | sylan | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ℕ )  →  ( 𝐹 ‘ 𝑛 )  ∈  ran  𝐹 ) | 
						
							| 20 |  | elssuni | ⊢ ( ( 𝐹 ‘ 𝑛 )  ∈  ran  𝐹  →  ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 21 | 19 20 | syl | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ℕ )  →  ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 22 | 16 21 | sylan2 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 23 | 22 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 24 | 23 | adantr | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∀ 𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 25 |  | iunss | ⊢ ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹  ↔  ∀ 𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 26 | 24 25 | sylibr | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ⊆  ∪  ran  𝐹 ) | 
						
							| 27 | 26 | sscond | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐸  ∖  ∪  ran  𝐹 )  ⊆  ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 28 | 4 | adantr | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  𝐸  ⊆  ℝ ) | 
						
							| 29 | 10 28 | sstrid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  ℝ ) | 
						
							| 30 |  | ovolss | ⊢ ( ( ( 𝐸  ∖  ∪  ran  𝐹 )  ⊆  ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ∧  ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  ⊆  ℝ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) )  ≤  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 31 | 27 29 30 | syl2anc | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) )  ≤  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 32 | 9 12 15 31 | leadd2dd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) ) )  ≤  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) ) | 
						
							| 33 |  | oveq2 | ⊢ ( 𝑧  =  1  →  ( 1 ... 𝑧 )  =  ( 1 ... 1 ) ) | 
						
							| 34 | 33 | iuneq1d | ⊢ ( 𝑧  =  1  →  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 35 | 34 | eleq1d | ⊢ ( 𝑧  =  1  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ↔  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) ) | 
						
							| 36 | 34 | ineq2d | ⊢ ( 𝑧  =  1  →  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 37 | 36 | fveq2d | ⊢ ( 𝑧  =  1  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 38 |  | fveq2 | ⊢ ( 𝑧  =  1  →  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) ) | 
						
							| 39 | 37 38 | eqeq12d | ⊢ ( 𝑧  =  1  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  ↔  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) ) ) | 
						
							| 40 | 35 39 | anbi12d | ⊢ ( 𝑧  =  1  →  ( ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) )  ↔  ( ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) ) ) ) | 
						
							| 41 | 40 | imbi2d | ⊢ ( 𝑧  =  1  →  ( ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) ) )  ↔  ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) ) ) ) ) | 
						
							| 42 |  | oveq2 | ⊢ ( 𝑧  =  𝑘  →  ( 1 ... 𝑧 )  =  ( 1 ... 𝑘 ) ) | 
						
							| 43 | 42 | iuneq1d | ⊢ ( 𝑧  =  𝑘  →  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 44 | 43 | eleq1d | ⊢ ( 𝑧  =  𝑘  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ↔  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) ) | 
						
							| 45 | 43 | ineq2d | ⊢ ( 𝑧  =  𝑘  →  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 46 | 45 | fveq2d | ⊢ ( 𝑧  =  𝑘  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 47 |  | fveq2 | ⊢ ( 𝑧  =  𝑘  →  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) | 
						
							| 48 | 46 47 | eqeq12d | ⊢ ( 𝑧  =  𝑘  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  ↔  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) ) | 
						
							| 49 | 44 48 | anbi12d | ⊢ ( 𝑧  =  𝑘  →  ( ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) )  ↔  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) ) ) | 
						
							| 50 | 49 | imbi2d | ⊢ ( 𝑧  =  𝑘  →  ( ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) ) )  ↔  ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) ) ) ) | 
						
							| 51 |  | oveq2 | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( 1 ... 𝑧 )  =  ( 1 ... ( 𝑘  +  1 ) ) ) | 
						
							| 52 | 51 | iuneq1d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 53 | 52 | eleq1d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ↔  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) ) | 
						
							| 54 | 52 | ineq2d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 55 | 54 | fveq2d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 56 |  | fveq2 | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 57 | 55 56 | eqeq12d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 )  ↔  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 58 | 53 57 | anbi12d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) )  ↔  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 59 | 58 | imbi2d | ⊢ ( 𝑧  =  ( 𝑘  +  1 )  →  ( ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑧 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑧 ) ) )  ↔  ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 60 |  | 1z | ⊢ 1  ∈  ℤ | 
						
							| 61 |  | fzsn | ⊢ ( 1  ∈  ℤ  →  ( 1 ... 1 )  =  { 1 } ) | 
						
							| 62 |  | iuneq1 | ⊢ ( ( 1 ... 1 )  =  { 1 }  →  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  { 1 } ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 63 | 60 61 62 | mp2b | ⊢ ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  { 1 } ( 𝐹 ‘ 𝑛 ) | 
						
							| 64 |  | 1ex | ⊢ 1  ∈  V | 
						
							| 65 |  | fveq2 | ⊢ ( 𝑛  =  1  →  ( 𝐹 ‘ 𝑛 )  =  ( 𝐹 ‘ 1 ) ) | 
						
							| 66 | 64 65 | iunxsn | ⊢ ∪  𝑛  ∈  { 1 } ( 𝐹 ‘ 𝑛 )  =  ( 𝐹 ‘ 1 ) | 
						
							| 67 | 63 66 | eqtri | ⊢ ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  =  ( 𝐹 ‘ 1 ) | 
						
							| 68 |  | 1nn | ⊢ 1  ∈  ℕ | 
						
							| 69 |  | ffvelcdm | ⊢ ( ( 𝐹 : ℕ ⟶ dom  vol  ∧  1  ∈  ℕ )  →  ( 𝐹 ‘ 1 )  ∈  dom  vol ) | 
						
							| 70 | 1 68 69 | sylancl | ⊢ ( 𝜑  →  ( 𝐹 ‘ 1 )  ∈  dom  vol ) | 
						
							| 71 | 67 70 | eqeltrid | ⊢ ( 𝜑  →  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) | 
						
							| 72 | 65 | ineq2d | ⊢ ( 𝑛  =  1  →  ( 𝐸  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) ) | 
						
							| 73 | 72 | fveq2d | ⊢ ( 𝑛  =  1  →  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) ) ) | 
						
							| 74 |  | fvex | ⊢ ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) )  ∈  V | 
						
							| 75 | 73 3 74 | fvmpt | ⊢ ( 1  ∈  ℕ  →  ( 𝐻 ‘ 1 )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) ) ) | 
						
							| 76 | 68 75 | ax-mp | ⊢ ( 𝐻 ‘ 1 )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) ) | 
						
							| 77 |  | seq1 | ⊢ ( 1  ∈  ℤ  →  ( seq 1 (  +  ,  𝐻 ) ‘ 1 )  =  ( 𝐻 ‘ 1 ) ) | 
						
							| 78 | 60 77 | ax-mp | ⊢ ( seq 1 (  +  ,  𝐻 ) ‘ 1 )  =  ( 𝐻 ‘ 1 ) | 
						
							| 79 | 67 | ineq2i | ⊢ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) | 
						
							| 80 | 79 | fveq2i | ⊢ ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 1 ) ) ) | 
						
							| 81 | 76 78 80 | 3eqtr4ri | ⊢ ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) | 
						
							| 82 | 71 81 | jctir | ⊢ ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 1 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 1 ) ) ) | 
						
							| 83 |  | peano2nn | ⊢ ( 𝑘  ∈  ℕ  →  ( 𝑘  +  1 )  ∈  ℕ ) | 
						
							| 84 |  | ffvelcdm | ⊢ ( ( 𝐹 : ℕ ⟶ dom  vol  ∧  ( 𝑘  +  1 )  ∈  ℕ )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  dom  vol ) | 
						
							| 85 | 1 83 84 | syl2an | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  dom  vol ) | 
						
							| 86 |  | unmbl | ⊢ ( ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  dom  vol )  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∈  dom  vol ) | 
						
							| 87 | 86 | ex | ⊢ ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  dom  vol  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∈  dom  vol ) ) | 
						
							| 88 | 85 87 | syl5com | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∈  dom  vol ) ) | 
						
							| 89 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  𝑘  ∈  ℕ ) | 
						
							| 90 |  | nnuz | ⊢ ℕ  =  ( ℤ≥ ‘ 1 ) | 
						
							| 91 | 89 90 | eleqtrdi | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  𝑘  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 92 |  | fzsuc | ⊢ ( 𝑘  ∈  ( ℤ≥ ‘ 1 )  →  ( 1 ... ( 𝑘  +  1 ) )  =  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } ) ) | 
						
							| 93 |  | iuneq1 | ⊢ ( ( 1 ... ( 𝑘  +  1 ) )  =  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } )  →  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 94 | 91 92 93 | 3syl | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  =  ∪  𝑛  ∈  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 95 |  | iunxun | ⊢ ∪  𝑛  ∈  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } ) ( 𝐹 ‘ 𝑛 )  =  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ∪  𝑛  ∈  { ( 𝑘  +  1 ) } ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 96 |  | ovex | ⊢ ( 𝑘  +  1 )  ∈  V | 
						
							| 97 |  | fveq2 | ⊢ ( 𝑛  =  ( 𝑘  +  1 )  →  ( 𝐹 ‘ 𝑛 )  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 98 | 96 97 | iunxsn | ⊢ ∪  𝑛  ∈  { ( 𝑘  +  1 ) } ( 𝐹 ‘ 𝑛 )  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) | 
						
							| 99 | 98 | uneq2i | ⊢ ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ∪  𝑛  ∈  { ( 𝑘  +  1 ) } ( 𝐹 ‘ 𝑛 ) )  =  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 100 | 95 99 | eqtri | ⊢ ∪  𝑛  ∈  ( ( 1 ... 𝑘 )  ∪  { ( 𝑘  +  1 ) } ) ( 𝐹 ‘ 𝑛 )  =  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 101 | 94 100 | eqtrdi | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  =  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 102 | 101 | eleq1d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ↔  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∈  dom  vol ) ) | 
						
							| 103 | 88 102 | sylibrd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  →  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) ) | 
						
							| 104 |  | oveq1 | ⊢ ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 105 |  | inss1 | ⊢ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸 | 
						
							| 106 | 105 28 | sstrid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ⊆  ℝ ) | 
						
							| 107 |  | ovolsscl | ⊢ ( ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ⊆  𝐸  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 108 | 105 4 7 107 | mp3an2ani | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ ) | 
						
							| 109 |  | mblsplit | ⊢ ( ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  dom  vol  ∧  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ⊆  ℝ  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  +  ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 110 | 85 106 108 109 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  +  ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 111 |  | in32 | ⊢ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ( ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 112 |  | inss2 | ⊢ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ⊆  ( 𝐹 ‘ ( 𝑘  +  1 ) ) | 
						
							| 113 | 83 | adantl | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝑘  +  1 )  ∈  ℕ ) | 
						
							| 114 | 113 90 | eleqtrdi | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝑘  +  1 )  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 115 |  | eluzfz2 | ⊢ ( ( 𝑘  +  1 )  ∈  ( ℤ≥ ‘ 1 )  →  ( 𝑘  +  1 )  ∈  ( 1 ... ( 𝑘  +  1 ) ) ) | 
						
							| 116 | 97 | ssiun2s | ⊢ ( ( 𝑘  +  1 )  ∈  ( 1 ... ( 𝑘  +  1 ) )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ⊆  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 117 | 114 115 116 | 3syl | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ⊆  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 118 | 112 117 | sstrid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ⊆  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 119 |  | dfss2 | ⊢ ( ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ⊆  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ↔  ( ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 120 | 118 119 | sylib | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 121 | 111 120 | eqtrid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 122 | 121 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 123 |  | indif2 | ⊢ ( 𝐸  ∩  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  =  ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 124 |  | uncom | ⊢ ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∪  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∪  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 125 | 101 124 | eqtr2di | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∪  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  =  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 126 | 2 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  Disj  𝑖  ∈  ℕ ( 𝐹 ‘ 𝑖 ) ) | 
						
							| 127 | 113 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  ( 𝑘  +  1 )  ∈  ℕ ) | 
						
							| 128 | 16 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  𝑛  ∈  ℕ ) | 
						
							| 129 | 128 | nnred | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  𝑛  ∈  ℝ ) | 
						
							| 130 |  | elfzle2 | ⊢ ( 𝑛  ∈  ( 1 ... 𝑘 )  →  𝑛  ≤  𝑘 ) | 
						
							| 131 | 130 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  𝑛  ≤  𝑘 ) | 
						
							| 132 | 89 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  𝑘  ∈  ℕ ) | 
						
							| 133 |  | nnleltp1 | ⊢ ( ( 𝑛  ∈  ℕ  ∧  𝑘  ∈  ℕ )  →  ( 𝑛  ≤  𝑘  ↔  𝑛  <  ( 𝑘  +  1 ) ) ) | 
						
							| 134 | 128 132 133 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  ( 𝑛  ≤  𝑘  ↔  𝑛  <  ( 𝑘  +  1 ) ) ) | 
						
							| 135 | 131 134 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  𝑛  <  ( 𝑘  +  1 ) ) | 
						
							| 136 | 129 135 | gtned | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  ( 𝑘  +  1 )  ≠  𝑛 ) | 
						
							| 137 |  | fveq2 | ⊢ ( 𝑖  =  ( 𝑘  +  1 )  →  ( 𝐹 ‘ 𝑖 )  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 138 |  | fveq2 | ⊢ ( 𝑖  =  𝑛  →  ( 𝐹 ‘ 𝑖 )  =  ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 139 | 137 138 | disji2 | ⊢ ( ( Disj  𝑖  ∈  ℕ ( 𝐹 ‘ 𝑖 )  ∧  ( ( 𝑘  +  1 )  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑘  +  1 )  ≠  𝑛 )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ∅ ) | 
						
							| 140 | 126 127 128 136 139 | syl121anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ℕ )  ∧  𝑛  ∈  ( 1 ... 𝑘 ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ∅ ) | 
						
							| 141 | 140 | iuneq2dv | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ∅ ) | 
						
							| 142 |  | iunin2 | ⊢ ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 143 |  | iun0 | ⊢ ∪  𝑛  ∈  ( 1 ... 𝑘 ) ∅  =  ∅ | 
						
							| 144 | 141 142 143 | 3eqtr3g | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  =  ∅ ) | 
						
							| 145 |  | uneqdifeq | ⊢ ( ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ⊆  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∧  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  =  ∅ )  →  ( ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∪  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  =  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ↔  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 146 | 117 144 145 | syl2anc | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∪  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) )  =  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ↔  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 147 | 125 146 | mpbid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) | 
						
							| 148 | 147 | ineq2d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐸  ∩  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  =  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 149 | 123 148 | eqtr3id | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  =  ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) | 
						
							| 150 | 149 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 151 | 122 150 | oveq12d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  +  ( vol* ‘ ( ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) )  ∖  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) )  =  ( ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) ) | 
						
							| 152 |  | inss1 | ⊢ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ⊆  𝐸 | 
						
							| 153 |  | ovolsscl | ⊢ ( ( ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) )  ⊆  𝐸  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  ∈  ℝ ) | 
						
							| 154 | 152 4 7 153 | mp3an2ani | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  ∈  ℝ ) | 
						
							| 155 | 154 | recnd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  ∈  ℂ ) | 
						
							| 156 | 15 | recnd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  ∈  ℂ ) | 
						
							| 157 | 155 156 | addcomd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) )  =  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 158 | 110 151 157 | 3eqtrd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 159 |  | seqp1 | ⊢ ( 𝑘  ∈  ( ℤ≥ ‘ 1 )  →  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( 𝐻 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 160 | 91 159 | syl | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( 𝐻 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 161 | 97 | ineq2d | ⊢ ( 𝑛  =  ( 𝑘  +  1 )  →  ( 𝐸  ∩  ( 𝐹 ‘ 𝑛 ) )  =  ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 162 | 161 | fveq2d | ⊢ ( 𝑛  =  ( 𝑘  +  1 )  →  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ 𝑛 ) ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 163 |  | fvex | ⊢ ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  ∈  V | 
						
							| 164 | 162 3 163 | fvmpt | ⊢ ( ( 𝑘  +  1 )  ∈  ℕ  →  ( 𝐻 ‘ ( 𝑘  +  1 ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 165 | 113 164 | syl | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( 𝐻 ‘ ( 𝑘  +  1 ) )  =  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 166 | 165 | oveq2d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( 𝐻 ‘ ( 𝑘  +  1 ) ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 167 | 160 166 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 168 | 158 167 | eqeq12d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) )  ↔  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) )  =  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∩  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) ) ) ) | 
						
							| 169 | 104 168 | imbitrrid | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 170 | 103 169 | anim12d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) )  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 171 | 170 | expcom | ⊢ ( 𝑘  ∈  ℕ  →  ( 𝜑  →  ( ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) )  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 172 | 171 | a2d | ⊢ ( 𝑘  ∈  ℕ  →  ( ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) )  →  ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... ( 𝑘  +  1 ) ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 173 | 41 50 59 50 82 172 | nnind | ⊢ ( 𝑘  ∈  ℕ  →  ( 𝜑  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) ) ) | 
						
							| 174 | 173 | impcom | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) ) | 
						
							| 175 | 174 | simprd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  =  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 ) ) | 
						
							| 176 | 175 | eqcomd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  =  ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) | 
						
							| 177 | 176 | oveq1d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) ) )  =  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) ) ) ) | 
						
							| 178 | 174 | simpld | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol ) | 
						
							| 179 |  | mblsplit | ⊢ ( ( ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 )  ∈  dom  vol  ∧  𝐸  ⊆  ℝ  ∧  ( vol* ‘ 𝐸 )  ∈  ℝ )  →  ( vol* ‘ 𝐸 )  =  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) ) | 
						
							| 180 | 178 28 7 179 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( vol* ‘ 𝐸 )  =  ( ( vol* ‘ ( 𝐸  ∩  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) )  +  ( vol* ‘ ( 𝐸  ∖  ∪  𝑛  ∈  ( 1 ... 𝑘 ) ( 𝐹 ‘ 𝑛 ) ) ) ) ) | 
						
							| 181 | 32 177 180 | 3brtr4d | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ℕ )  →  ( ( seq 1 (  +  ,  𝐻 ) ‘ 𝑘 )  +  ( vol* ‘ ( 𝐸  ∖  ∪  ran  𝐹 ) ) )  ≤  ( vol* ‘ 𝐸 ) ) |