| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eqid |  |-  [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear | 
						
							| 2 |  | fveq2 |  |-  ( n = N -> ( EE ` n ) = ( EE ` N ) ) | 
						
							| 3 | 2 | eleq2d |  |-  ( n = N -> ( A e. ( EE ` n ) <-> A e. ( EE ` N ) ) ) | 
						
							| 4 | 2 | eleq2d |  |-  ( n = N -> ( B e. ( EE ` n ) <-> B e. ( EE ` N ) ) ) | 
						
							| 5 | 3 4 | 3anbi12d |  |-  ( n = N -> ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) <-> ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) ) | 
						
							| 6 | 5 | anbi1d |  |-  ( n = N -> ( ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) <-> ( ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 7 | 6 | rspcev |  |-  ( ( N e. NN /\ ( ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) -> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) | 
						
							| 8 | 1 7 | mpanr2 |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) | 
						
							| 9 |  | simpr1 |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> A e. ( EE ` N ) ) | 
						
							| 10 |  | simpr2 |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> B e. ( EE ` N ) ) | 
						
							| 11 |  | colinearex |  |-  Colinear e. _V | 
						
							| 12 | 11 | cnvex |  |-  `' Colinear e. _V | 
						
							| 13 |  | ecexg |  |-  ( `' Colinear e. _V -> [ <. A , B >. ] `' Colinear e. _V ) | 
						
							| 14 | 12 13 | ax-mp |  |-  [ <. A , B >. ] `' Colinear e. _V | 
						
							| 15 |  | eleq1 |  |-  ( a = A -> ( a e. ( EE ` n ) <-> A e. ( EE ` n ) ) ) | 
						
							| 16 |  | neeq1 |  |-  ( a = A -> ( a =/= b <-> A =/= b ) ) | 
						
							| 17 | 15 16 | 3anbi13d |  |-  ( a = A -> ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) <-> ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) ) ) | 
						
							| 18 |  | opeq1 |  |-  ( a = A -> <. a , b >. = <. A , b >. ) | 
						
							| 19 | 18 | eceq1d |  |-  ( a = A -> [ <. a , b >. ] `' Colinear = [ <. A , b >. ] `' Colinear ) | 
						
							| 20 | 19 | eqeq2d |  |-  ( a = A -> ( l = [ <. a , b >. ] `' Colinear <-> l = [ <. A , b >. ] `' Colinear ) ) | 
						
							| 21 | 17 20 | anbi12d |  |-  ( a = A -> ( ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) <-> ( ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) /\ l = [ <. A , b >. ] `' Colinear ) ) ) | 
						
							| 22 | 21 | rexbidv |  |-  ( a = A -> ( E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) <-> E. n e. NN ( ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) /\ l = [ <. A , b >. ] `' Colinear ) ) ) | 
						
							| 23 |  | eleq1 |  |-  ( b = B -> ( b e. ( EE ` n ) <-> B e. ( EE ` n ) ) ) | 
						
							| 24 |  | neeq2 |  |-  ( b = B -> ( A =/= b <-> A =/= B ) ) | 
						
							| 25 | 23 24 | 3anbi23d |  |-  ( b = B -> ( ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) <-> ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) ) ) | 
						
							| 26 |  | opeq2 |  |-  ( b = B -> <. A , b >. = <. A , B >. ) | 
						
							| 27 | 26 | eceq1d |  |-  ( b = B -> [ <. A , b >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) | 
						
							| 28 | 27 | eqeq2d |  |-  ( b = B -> ( l = [ <. A , b >. ] `' Colinear <-> l = [ <. A , B >. ] `' Colinear ) ) | 
						
							| 29 | 25 28 | anbi12d |  |-  ( b = B -> ( ( ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) /\ l = [ <. A , b >. ] `' Colinear ) <-> ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ l = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 30 | 29 | rexbidv |  |-  ( b = B -> ( E. n e. NN ( ( A e. ( EE ` n ) /\ b e. ( EE ` n ) /\ A =/= b ) /\ l = [ <. A , b >. ] `' Colinear ) <-> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ l = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 31 |  | eqeq1 |  |-  ( l = [ <. A , B >. ] `' Colinear -> ( l = [ <. A , B >. ] `' Colinear <-> [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) | 
						
							| 32 | 31 | anbi2d |  |-  ( l = [ <. A , B >. ] `' Colinear -> ( ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ l = [ <. A , B >. ] `' Colinear ) <-> ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 33 | 32 | rexbidv |  |-  ( l = [ <. A , B >. ] `' Colinear -> ( E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ l = [ <. A , B >. ] `' Colinear ) <-> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 34 | 22 30 33 | eloprabg |  |-  ( ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ [ <. A , B >. ] `' Colinear e. _V ) -> ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } <-> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 35 | 14 34 | mp3an3 |  |-  ( ( A e. ( EE ` N ) /\ B e. ( EE ` N ) ) -> ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } <-> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 36 | 9 10 35 | syl2anc |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } <-> E. n e. NN ( ( A e. ( EE ` n ) /\ B e. ( EE ` n ) /\ A =/= B ) /\ [ <. A , B >. ] `' Colinear = [ <. A , B >. ] `' Colinear ) ) ) | 
						
							| 37 | 8 36 | mpbird |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } ) | 
						
							| 38 |  | df-ov |  |-  ( A Line B ) = ( Line ` <. A , B >. ) | 
						
							| 39 |  | df-br |  |-  ( <. A , B >. Line [ <. A , B >. ] `' Colinear <-> <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. Line ) | 
						
							| 40 |  | df-line2 |  |-  Line = { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } | 
						
							| 41 | 40 | eleq2i |  |-  ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. Line <-> <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } ) | 
						
							| 42 | 39 41 | bitri |  |-  ( <. A , B >. Line [ <. A , B >. ] `' Colinear <-> <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } ) | 
						
							| 43 |  | funline |  |-  Fun Line | 
						
							| 44 |  | funbrfv |  |-  ( Fun Line -> ( <. A , B >. Line [ <. A , B >. ] `' Colinear -> ( Line ` <. A , B >. ) = [ <. A , B >. ] `' Colinear ) ) | 
						
							| 45 | 43 44 | ax-mp |  |-  ( <. A , B >. Line [ <. A , B >. ] `' Colinear -> ( Line ` <. A , B >. ) = [ <. A , B >. ] `' Colinear ) | 
						
							| 46 | 42 45 | sylbir |  |-  ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } -> ( Line ` <. A , B >. ) = [ <. A , B >. ] `' Colinear ) | 
						
							| 47 | 38 46 | eqtrid |  |-  ( <. <. A , B >. , [ <. A , B >. ] `' Colinear >. e. { <. <. a , b >. , l >. | E. n e. NN ( ( a e. ( EE ` n ) /\ b e. ( EE ` n ) /\ a =/= b ) /\ l = [ <. a , b >. ] `' Colinear ) } -> ( A Line B ) = [ <. A , B >. ] `' Colinear ) | 
						
							| 48 | 37 47 | syl |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> ( A Line B ) = [ <. A , B >. ] `' Colinear ) | 
						
							| 49 |  | opex |  |-  <. A , B >. e. _V | 
						
							| 50 |  | dfec2 |  |-  ( <. A , B >. e. _V -> [ <. A , B >. ] `' Colinear = { x | <. A , B >. `' Colinear x } ) | 
						
							| 51 | 49 50 | ax-mp |  |-  [ <. A , B >. ] `' Colinear = { x | <. A , B >. `' Colinear x } | 
						
							| 52 |  | vex |  |-  x e. _V | 
						
							| 53 | 49 52 | brcnv |  |-  ( <. A , B >. `' Colinear x <-> x Colinear <. A , B >. ) | 
						
							| 54 | 53 | abbii |  |-  { x | <. A , B >. `' Colinear x } = { x | x Colinear <. A , B >. } | 
						
							| 55 | 51 54 | eqtri |  |-  [ <. A , B >. ] `' Colinear = { x | x Colinear <. A , B >. } | 
						
							| 56 | 48 55 | eqtrdi |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ A =/= B ) ) -> ( A Line B ) = { x | x Colinear <. A , B >. } ) |