| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rrxspheres.e | ⊢ 𝐸  =  ( ℝ^ ‘ 𝐼 ) | 
						
							| 2 |  | rrxspheres.p | ⊢ 𝑃  =  ( ℝ  ↑m  𝐼 ) | 
						
							| 3 |  | rrxspheres.d | ⊢ 𝐷  =  ( dist ‘ 𝐸 ) | 
						
							| 4 |  | rrxspheres.s | ⊢ 𝑆  =  ( Sphere ‘ 𝐸 ) | 
						
							| 5 | 1 | fvexi | ⊢ 𝐸  ∈  V | 
						
							| 6 |  | id | ⊢ ( 𝐼  ∈  Fin  →  𝐼  ∈  Fin ) | 
						
							| 7 |  | eqid | ⊢ ( Base ‘ 𝐸 )  =  ( Base ‘ 𝐸 ) | 
						
							| 8 | 6 1 7 | rrxbasefi | ⊢ ( 𝐼  ∈  Fin  →  ( Base ‘ 𝐸 )  =  ( ℝ  ↑m  𝐼 ) ) | 
						
							| 9 | 2 8 | eqtr4id | ⊢ ( 𝐼  ∈  Fin  →  𝑃  =  ( Base ‘ 𝐸 ) ) | 
						
							| 10 | 9 | eleq2d | ⊢ ( 𝐼  ∈  Fin  →  ( 𝑀  ∈  𝑃  ↔  𝑀  ∈  ( Base ‘ 𝐸 ) ) ) | 
						
							| 11 | 10 | biimpa | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃 )  →  𝑀  ∈  ( Base ‘ 𝐸 ) ) | 
						
							| 12 | 11 | 3adant3 | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  𝑀  ∈  ( Base ‘ 𝐸 ) ) | 
						
							| 13 | 12 | adantl | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  𝑀  ∈  ( Base ‘ 𝐸 ) ) | 
						
							| 14 |  | rexr | ⊢ ( 𝑅  ∈  ℝ  →  𝑅  ∈  ℝ* ) | 
						
							| 15 | 14 | 3ad2ant3 | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  𝑅  ∈  ℝ* ) | 
						
							| 16 | 15 | anim2i | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  ( 0  ≤  𝑅  ∧  𝑅  ∈  ℝ* ) ) | 
						
							| 17 | 16 | ancomd | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  ( 𝑅  ∈  ℝ*  ∧  0  ≤  𝑅 ) ) | 
						
							| 18 |  | elxrge0 | ⊢ ( 𝑅  ∈  ( 0 [,] +∞ )  ↔  ( 𝑅  ∈  ℝ*  ∧  0  ≤  𝑅 ) ) | 
						
							| 19 | 17 18 | sylibr | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  𝑅  ∈  ( 0 [,] +∞ ) ) | 
						
							| 20 | 7 4 3 | sphere | ⊢ ( ( 𝐸  ∈  V  ∧  𝑀  ∈  ( Base ‘ 𝐸 )  ∧  𝑅  ∈  ( 0 [,] +∞ ) )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 21 | 5 13 19 20 | mp3an2i | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 22 |  | simp1 | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  𝐼  ∈  Fin ) | 
						
							| 23 | 22 1 7 | rrxbasefi | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( Base ‘ 𝐸 )  =  ( ℝ  ↑m  𝐼 ) ) | 
						
							| 24 | 23 2 | eqtr4di | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( Base ‘ 𝐸 )  =  𝑃 ) | 
						
							| 25 | 24 | adantl | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  ( Base ‘ 𝐸 )  =  𝑃 ) | 
						
							| 26 | 25 | rabeqdv | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 }  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 27 | 21 26 | eqtrd | ⊢ ( ( 0  ≤  𝑅  ∧  ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ ) )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 28 | 27 | ex | ⊢ ( 0  ≤  𝑅  →  ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) ) | 
						
							| 29 | 7 4 3 | spheres | ⊢ ( 𝐸  ∈  V  →  𝑆  =  ( 𝑥  ∈  ( Base ‘ 𝐸 ) ,  𝑟  ∈  ( 0 [,] +∞ )  ↦  { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑥 )  =  𝑟 } ) ) | 
						
							| 30 | 5 29 | ax-mp | ⊢ 𝑆  =  ( 𝑥  ∈  ( Base ‘ 𝐸 ) ,  𝑟  ∈  ( 0 [,] +∞ )  ↦  { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑥 )  =  𝑟 } ) | 
						
							| 31 |  | fvex | ⊢ ( Base ‘ 𝐸 )  ∈  V | 
						
							| 32 | 31 | rabex | ⊢ { 𝑝  ∈  ( Base ‘ 𝐸 )  ∣  ( 𝑝 𝐷 𝑥 )  =  𝑟 }  ∈  V | 
						
							| 33 | 30 32 | dmmpo | ⊢ dom  𝑆  =  ( ( Base ‘ 𝐸 )  ×  ( 0 [,] +∞ ) ) | 
						
							| 34 |  | 0xr | ⊢ 0  ∈  ℝ* | 
						
							| 35 |  | pnfxr | ⊢ +∞  ∈  ℝ* | 
						
							| 36 | 34 35 | pm3.2i | ⊢ ( 0  ∈  ℝ*  ∧  +∞  ∈  ℝ* ) | 
						
							| 37 |  | elicc1 | ⊢ ( ( 0  ∈  ℝ*  ∧  +∞  ∈  ℝ* )  →  ( 𝑅  ∈  ( 0 [,] +∞ )  ↔  ( 𝑅  ∈  ℝ*  ∧  0  ≤  𝑅  ∧  𝑅  ≤  +∞ ) ) ) | 
						
							| 38 | 36 37 | mp1i | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( 𝑅  ∈  ( 0 [,] +∞ )  ↔  ( 𝑅  ∈  ℝ*  ∧  0  ≤  𝑅  ∧  𝑅  ≤  +∞ ) ) ) | 
						
							| 39 |  | simp2 | ⊢ ( ( 𝑅  ∈  ℝ*  ∧  0  ≤  𝑅  ∧  𝑅  ≤  +∞ )  →  0  ≤  𝑅 ) | 
						
							| 40 | 38 39 | biimtrdi | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( 𝑅  ∈  ( 0 [,] +∞ )  →  0  ≤  𝑅 ) ) | 
						
							| 41 | 40 | con3d | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( ¬  0  ≤  𝑅  →  ¬  𝑅  ∈  ( 0 [,] +∞ ) ) ) | 
						
							| 42 | 41 | imp | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ¬  𝑅  ∈  ( 0 [,] +∞ ) ) | 
						
							| 43 | 42 | intnand | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ¬  ( 𝑀  ∈  ( Base ‘ 𝐸 )  ∧  𝑅  ∈  ( 0 [,] +∞ ) ) ) | 
						
							| 44 |  | ndmovg | ⊢ ( ( dom  𝑆  =  ( ( Base ‘ 𝐸 )  ×  ( 0 [,] +∞ ) )  ∧  ¬  ( 𝑀  ∈  ( Base ‘ 𝐸 )  ∧  𝑅  ∈  ( 0 [,] +∞ ) ) )  →  ( 𝑀 𝑆 𝑅 )  =  ∅ ) | 
						
							| 45 | 33 43 44 | sylancr | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ( 𝑀 𝑆 𝑅 )  =  ∅ ) | 
						
							| 46 | 1 | fveq2i | ⊢ ( dist ‘ 𝐸 )  =  ( dist ‘ ( ℝ^ ‘ 𝐼 ) ) | 
						
							| 47 | 3 46 | eqtri | ⊢ 𝐷  =  ( dist ‘ ( ℝ^ ‘ 𝐼 ) ) | 
						
							| 48 | 47 | rrxmetfi | ⊢ ( 𝐼  ∈  Fin  →  𝐷  ∈  ( Met ‘ ( ℝ  ↑m  𝐼 ) ) ) | 
						
							| 49 | 48 | 3ad2ant1 | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  𝐷  ∈  ( Met ‘ ( ℝ  ↑m  𝐼 ) ) ) | 
						
							| 50 | 49 | adantr | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  𝐷  ∈  ( Met ‘ ( ℝ  ↑m  𝐼 ) ) ) | 
						
							| 51 | 2 | fveq2i | ⊢ ( Met ‘ 𝑃 )  =  ( Met ‘ ( ℝ  ↑m  𝐼 ) ) | 
						
							| 52 | 50 51 | eleqtrrdi | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  𝐷  ∈  ( Met ‘ 𝑃 ) ) | 
						
							| 53 |  | simpr | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  𝑝  ∈  𝑃 ) | 
						
							| 54 |  | simp2 | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  𝑀  ∈  𝑃 ) | 
						
							| 55 | 54 | adantr | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  𝑀  ∈  𝑃 ) | 
						
							| 56 |  | metge0 | ⊢ ( ( 𝐷  ∈  ( Met ‘ 𝑃 )  ∧  𝑝  ∈  𝑃  ∧  𝑀  ∈  𝑃 )  →  0  ≤  ( 𝑝 𝐷 𝑀 ) ) | 
						
							| 57 | 52 53 55 56 | syl3anc | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  0  ≤  ( 𝑝 𝐷 𝑀 ) ) | 
						
							| 58 |  | breq2 | ⊢ ( ( 𝑝 𝐷 𝑀 )  =  𝑅  →  ( 0  ≤  ( 𝑝 𝐷 𝑀 )  ↔  0  ≤  𝑅 ) ) | 
						
							| 59 | 57 58 | syl5ibcom | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  ( ( 𝑝 𝐷 𝑀 )  =  𝑅  →  0  ≤  𝑅 ) ) | 
						
							| 60 | 59 | con3d | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  𝑝  ∈  𝑃 )  →  ( ¬  0  ≤  𝑅  →  ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) ) | 
						
							| 61 | 60 | impancom | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ( 𝑝  ∈  𝑃  →  ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) ) | 
						
							| 62 | 61 | imp | ⊢ ( ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  ∧  𝑝  ∈  𝑃 )  →  ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) | 
						
							| 63 | 62 | ralrimiva | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ∀ 𝑝  ∈  𝑃 ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) | 
						
							| 64 |  | eqcom | ⊢ ( ∅  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 }  ↔  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 }  =  ∅ ) | 
						
							| 65 |  | rabeq0 | ⊢ ( { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 }  =  ∅  ↔  ∀ 𝑝  ∈  𝑃 ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) | 
						
							| 66 | 64 65 | bitri | ⊢ ( ∅  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 }  ↔  ∀ 𝑝  ∈  𝑃 ¬  ( 𝑝 𝐷 𝑀 )  =  𝑅 ) | 
						
							| 67 | 63 66 | sylibr | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ∅  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 68 | 45 67 | eqtrd | ⊢ ( ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  ∧  ¬  0  ≤  𝑅 )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) | 
						
							| 69 | 68 | expcom | ⊢ ( ¬  0  ≤  𝑅  →  ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) ) | 
						
							| 70 | 28 69 | pm2.61i | ⊢ ( ( 𝐼  ∈  Fin  ∧  𝑀  ∈  𝑃  ∧  𝑅  ∈  ℝ )  →  ( 𝑀 𝑆 𝑅 )  =  { 𝑝  ∈  𝑃  ∣  ( 𝑝 𝐷 𝑀 )  =  𝑅 } ) |