| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eengstr |  |-  ( N e. NN -> ( EEG ` N ) Struct <. 1 , ; 1 7 >. ) | 
						
							| 2 |  | fvexd |  |-  ( N e. NN -> ( EE ` N ) e. _V ) | 
						
							| 3 |  | opex |  |-  <. ( Base ` ndx ) , ( EE ` N ) >. e. _V | 
						
							| 4 | 3 | prid1 |  |-  <. ( Base ` ndx ) , ( EE ` N ) >. e. { <. ( Base ` ndx ) , ( EE ` N ) >. , <. ( dist ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> sum_ i e. ( 1 ... N ) ( ( ( x ` i ) - ( y ` i ) ) ^ 2 ) ) >. } | 
						
							| 5 |  | elun1 |  |-  ( <. ( Base ` ndx ) , ( EE ` N ) >. e. { <. ( Base ` ndx ) , ( EE ` N ) >. , <. ( dist ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> sum_ i e. ( 1 ... N ) ( ( ( x ` i ) - ( y ` i ) ) ^ 2 ) ) >. } -> <. ( Base ` ndx ) , ( EE ` N ) >. e. ( { <. ( Base ` ndx ) , ( EE ` N ) >. , <. ( dist ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> sum_ i e. ( 1 ... N ) ( ( ( x ` i ) - ( y ` i ) ) ^ 2 ) ) >. } u. { <. ( Itv ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> { z e. ( EE ` N ) | z Btwn <. x , y >. } ) >. , <. ( LineG ` ndx ) , ( x e. ( EE ` N ) , y e. ( ( EE ` N ) \ { x } ) |-> { z e. ( EE ` N ) | ( z Btwn <. x , y >. \/ x Btwn <. z , y >. \/ y Btwn <. x , z >. ) } ) >. } ) ) | 
						
							| 6 | 4 5 | ax-mp |  |-  <. ( Base ` ndx ) , ( EE ` N ) >. e. ( { <. ( Base ` ndx ) , ( EE ` N ) >. , <. ( dist ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> sum_ i e. ( 1 ... N ) ( ( ( x ` i ) - ( y ` i ) ) ^ 2 ) ) >. } u. { <. ( Itv ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> { z e. ( EE ` N ) | z Btwn <. x , y >. } ) >. , <. ( LineG ` ndx ) , ( x e. ( EE ` N ) , y e. ( ( EE ` N ) \ { x } ) |-> { z e. ( EE ` N ) | ( z Btwn <. x , y >. \/ x Btwn <. z , y >. \/ y Btwn <. x , z >. ) } ) >. } ) | 
						
							| 7 |  | eengv |  |-  ( N e. NN -> ( EEG ` N ) = ( { <. ( Base ` ndx ) , ( EE ` N ) >. , <. ( dist ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> sum_ i e. ( 1 ... N ) ( ( ( x ` i ) - ( y ` i ) ) ^ 2 ) ) >. } u. { <. ( Itv ` ndx ) , ( x e. ( EE ` N ) , y e. ( EE ` N ) |-> { z e. ( EE ` N ) | z Btwn <. x , y >. } ) >. , <. ( LineG ` ndx ) , ( x e. ( EE ` N ) , y e. ( ( EE ` N ) \ { x } ) |-> { z e. ( EE ` N ) | ( z Btwn <. x , y >. \/ x Btwn <. z , y >. \/ y Btwn <. x , z >. ) } ) >. } ) ) | 
						
							| 8 | 6 7 | eleqtrrid |  |-  ( N e. NN -> <. ( Base ` ndx ) , ( EE ` N ) >. e. ( EEG ` N ) ) | 
						
							| 9 | 1 2 8 | opelstrbas |  |-  ( N e. NN -> ( EE ` N ) = ( Base ` ( EEG ` N ) ) ) |