| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ebtwntg.1 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ ) | 
						
							| 2 |  | ebtwntg.2 | ⊢ 𝑃  =  ( Base ‘ ( EEG ‘ 𝑁 ) ) | 
						
							| 3 |  | ebtwntg.3 | ⊢ 𝐼  =  ( Itv ‘ ( EEG ‘ 𝑁 ) ) | 
						
							| 4 |  | ebtwntg.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑃 ) | 
						
							| 5 |  | ebtwntg.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑃 ) | 
						
							| 6 |  | ebtwntg.z | ⊢ ( 𝜑  →  𝑍  ∈  𝑃 ) | 
						
							| 7 |  | itvid | ⊢ Itv  =  Slot  ( Itv ‘ ndx ) | 
						
							| 8 |  | fvexd | ⊢ ( 𝜑  →  ( EEG ‘ 𝑁 )  ∈  V ) | 
						
							| 9 |  | eengstr | ⊢ ( 𝑁  ∈  ℕ  →  ( EEG ‘ 𝑁 )  Struct  〈 1 ,  ; 1 7 〉 ) | 
						
							| 10 | 1 9 | syl | ⊢ ( 𝜑  →  ( EEG ‘ 𝑁 )  Struct  〈 1 ,  ; 1 7 〉 ) | 
						
							| 11 |  | structn0fun | ⊢ ( ( EEG ‘ 𝑁 )  Struct  〈 1 ,  ; 1 7 〉  →  Fun  ( ( EEG ‘ 𝑁 )  ∖  { ∅ } ) ) | 
						
							| 12 | 10 11 | syl | ⊢ ( 𝜑  →  Fun  ( ( EEG ‘ 𝑁 )  ∖  { ∅ } ) ) | 
						
							| 13 |  | structcnvcnv | ⊢ ( ( EEG ‘ 𝑁 )  Struct  〈 1 ,  ; 1 7 〉  →  ◡ ◡ ( EEG ‘ 𝑁 )  =  ( ( EEG ‘ 𝑁 )  ∖  { ∅ } ) ) | 
						
							| 14 | 10 13 | syl | ⊢ ( 𝜑  →  ◡ ◡ ( EEG ‘ 𝑁 )  =  ( ( EEG ‘ 𝑁 )  ∖  { ∅ } ) ) | 
						
							| 15 | 14 | funeqd | ⊢ ( 𝜑  →  ( Fun  ◡ ◡ ( EEG ‘ 𝑁 )  ↔  Fun  ( ( EEG ‘ 𝑁 )  ∖  { ∅ } ) ) ) | 
						
							| 16 | 12 15 | mpbird | ⊢ ( 𝜑  →  Fun  ◡ ◡ ( EEG ‘ 𝑁 ) ) | 
						
							| 17 |  | opex | ⊢ 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  V | 
						
							| 18 | 17 | prid1 | ⊢ 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 } | 
						
							| 19 |  | elun2 | ⊢ ( 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 }  →  〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  ( { 〈 ( Base ‘ ndx ) ,  ( 𝔼 ‘ 𝑁 ) 〉 ,  〈 ( dist ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  Σ 𝑖  ∈  ( 1 ... 𝑁 ) ( ( ( 𝑥 ‘ 𝑖 )  −  ( 𝑦 ‘ 𝑖 ) ) ↑ 2 ) ) 〉 }  ∪  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 } ) ) | 
						
							| 20 | 18 19 | ax-mp | ⊢ 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  ( { 〈 ( Base ‘ ndx ) ,  ( 𝔼 ‘ 𝑁 ) 〉 ,  〈 ( dist ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  Σ 𝑖  ∈  ( 1 ... 𝑁 ) ( ( ( 𝑥 ‘ 𝑖 )  −  ( 𝑦 ‘ 𝑖 ) ) ↑ 2 ) ) 〉 }  ∪  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 } ) | 
						
							| 21 |  | eengv | ⊢ ( 𝑁  ∈  ℕ  →  ( EEG ‘ 𝑁 )  =  ( { 〈 ( Base ‘ ndx ) ,  ( 𝔼 ‘ 𝑁 ) 〉 ,  〈 ( dist ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  Σ 𝑖  ∈  ( 1 ... 𝑁 ) ( ( ( 𝑥 ‘ 𝑖 )  −  ( 𝑦 ‘ 𝑖 ) ) ↑ 2 ) ) 〉 }  ∪  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 } ) ) | 
						
							| 22 | 1 21 | syl | ⊢ ( 𝜑  →  ( EEG ‘ 𝑁 )  =  ( { 〈 ( Base ‘ ndx ) ,  ( 𝔼 ‘ 𝑁 ) 〉 ,  〈 ( dist ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  Σ 𝑖  ∈  ( 1 ... 𝑁 ) ( ( ( 𝑥 ‘ 𝑖 )  −  ( 𝑦 ‘ 𝑖 ) ) ↑ 2 ) ) 〉 }  ∪  { 〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉 ,  〈 ( LineG ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( ( 𝔼 ‘ 𝑁 )  ∖  { 𝑥 } )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ∨  𝑥  Btwn  〈 𝑧 ,  𝑦 〉  ∨  𝑦  Btwn  〈 𝑥 ,  𝑧 〉 ) } ) 〉 } ) ) | 
						
							| 23 | 20 22 | eleqtrrid | ⊢ ( 𝜑  →  〈 ( Itv ‘ ndx ) ,  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) 〉  ∈  ( EEG ‘ 𝑁 ) ) | 
						
							| 24 |  | fvex | ⊢ ( 𝔼 ‘ 𝑁 )  ∈  V | 
						
							| 25 | 24 24 | mpoex | ⊢ ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } )  ∈  V | 
						
							| 26 | 25 | a1i | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } )  ∈  V ) | 
						
							| 27 | 7 8 16 23 26 | strfv2d | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } )  =  ( Itv ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 28 | 3 27 | eqtr4id | ⊢ ( 𝜑  →  𝐼  =  ( 𝑥  ∈  ( 𝔼 ‘ 𝑁 ) ,  𝑦  ∈  ( 𝔼 ‘ 𝑁 )  ↦  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 } ) ) | 
						
							| 29 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑥  =  𝑋  ∧  𝑦  =  𝑌 ) )  →  𝑥  =  𝑋 ) | 
						
							| 30 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑥  =  𝑋  ∧  𝑦  =  𝑌 ) )  →  𝑦  =  𝑌 ) | 
						
							| 31 | 29 30 | opeq12d | ⊢ ( ( 𝜑  ∧  ( 𝑥  =  𝑋  ∧  𝑦  =  𝑌 ) )  →  〈 𝑥 ,  𝑦 〉  =  〈 𝑋 ,  𝑌 〉 ) | 
						
							| 32 | 31 | breq2d | ⊢ ( ( 𝜑  ∧  ( 𝑥  =  𝑋  ∧  𝑦  =  𝑌 ) )  →  ( 𝑧  Btwn  〈 𝑥 ,  𝑦 〉  ↔  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 33 | 32 | rabbidv | ⊢ ( ( 𝜑  ∧  ( 𝑥  =  𝑋  ∧  𝑦  =  𝑌 ) )  →  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑥 ,  𝑦 〉 }  =  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 } ) | 
						
							| 34 | 4 2 | eleqtrdi | ⊢ ( 𝜑  →  𝑋  ∈  ( Base ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 35 |  | eengbas | ⊢ ( 𝑁  ∈  ℕ  →  ( 𝔼 ‘ 𝑁 )  =  ( Base ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 36 | 1 35 | syl | ⊢ ( 𝜑  →  ( 𝔼 ‘ 𝑁 )  =  ( Base ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 37 | 34 36 | eleqtrrd | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 38 | 5 2 | eleqtrdi | ⊢ ( 𝜑  →  𝑌  ∈  ( Base ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 39 | 38 36 | eleqtrrd | ⊢ ( 𝜑  →  𝑌  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 40 | 24 | rabex | ⊢ { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 }  ∈  V | 
						
							| 41 | 40 | a1i | ⊢ ( 𝜑  →  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 }  ∈  V ) | 
						
							| 42 | 28 33 37 39 41 | ovmpod | ⊢ ( 𝜑  →  ( 𝑋 𝐼 𝑌 )  =  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 } ) | 
						
							| 43 | 42 | eleq2d | ⊢ ( 𝜑  →  ( 𝑍  ∈  ( 𝑋 𝐼 𝑌 )  ↔  𝑍  ∈  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 } ) ) | 
						
							| 44 | 6 2 | eleqtrdi | ⊢ ( 𝜑  →  𝑍  ∈  ( Base ‘ ( EEG ‘ 𝑁 ) ) ) | 
						
							| 45 | 44 36 | eleqtrrd | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 46 |  | breq1 | ⊢ ( 𝑧  =  𝑍  →  ( 𝑧  Btwn  〈 𝑋 ,  𝑌 〉  ↔  𝑍  Btwn  〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 47 | 46 | elrab3 | ⊢ ( 𝑍  ∈  ( 𝔼 ‘ 𝑁 )  →  ( 𝑍  ∈  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 }  ↔  𝑍  Btwn  〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 48 | 45 47 | syl | ⊢ ( 𝜑  →  ( 𝑍  ∈  { 𝑧  ∈  ( 𝔼 ‘ 𝑁 )  ∣  𝑧  Btwn  〈 𝑋 ,  𝑌 〉 }  ↔  𝑍  Btwn  〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 49 | 43 48 | bitr2d | ⊢ ( 𝜑  →  ( 𝑍  Btwn  〈 𝑋 ,  𝑌 〉  ↔  𝑍  ∈  ( 𝑋 𝐼 𝑌 ) ) ) |