| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xpsds.t |  |-  T = ( R Xs. S ) | 
						
							| 2 |  | xpsds.x |  |-  X = ( Base ` R ) | 
						
							| 3 |  | xpsds.y |  |-  Y = ( Base ` S ) | 
						
							| 4 |  | xpsds.1 |  |-  ( ph -> R e. V ) | 
						
							| 5 |  | xpsds.2 |  |-  ( ph -> S e. W ) | 
						
							| 6 |  | xpsds.p |  |-  P = ( dist ` T ) | 
						
							| 7 |  | xpsds.m |  |-  M = ( ( dist ` R ) |` ( X X. X ) ) | 
						
							| 8 |  | xpsds.n |  |-  N = ( ( dist ` S ) |` ( Y X. Y ) ) | 
						
							| 9 |  | xpsds.3 |  |-  ( ph -> M e. ( *Met ` X ) ) | 
						
							| 10 |  | xpsds.4 |  |-  ( ph -> N e. ( *Met ` Y ) ) | 
						
							| 11 |  | xpsds.a |  |-  ( ph -> A e. X ) | 
						
							| 12 |  | xpsds.b |  |-  ( ph -> B e. Y ) | 
						
							| 13 |  | xpsds.c |  |-  ( ph -> C e. X ) | 
						
							| 14 |  | xpsds.d |  |-  ( ph -> D e. Y ) | 
						
							| 15 |  | eqid |  |-  ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) = ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) | 
						
							| 16 |  | eqid |  |-  ( Scalar ` R ) = ( Scalar ` R ) | 
						
							| 17 |  | eqid |  |-  ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) = ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) | 
						
							| 18 | 1 2 3 4 5 15 16 17 | xpsval |  |-  ( ph -> T = ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) "s ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) ) | 
						
							| 19 | 1 2 3 4 5 15 16 17 | xpsrnbas |  |-  ( ph -> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) = ( Base ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) ) | 
						
							| 20 | 15 | xpsff1o2 |  |-  ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) -1-1-onto-> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) | 
						
							| 21 |  | f1ocnv |  |-  ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) -1-1-onto-> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) -> `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) -1-1-onto-> ( X X. Y ) ) | 
						
							| 22 | 20 21 | mp1i |  |-  ( ph -> `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) -1-1-onto-> ( X X. Y ) ) | 
						
							| 23 |  | ovexd |  |-  ( ph -> ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) e. _V ) | 
						
							| 24 |  | eqid |  |-  ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) = ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) | 
						
							| 25 | 1 2 3 4 5 6 7 8 9 10 | xpsxmetlem |  |-  ( ph -> ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) e. ( *Met ` ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) | 
						
							| 26 |  | ssid |  |-  ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) C_ ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) | 
						
							| 27 |  | xmetres2 |  |-  ( ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) e. ( *Met ` ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) /\ ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) C_ ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) -> ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) e. ( *Met ` ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) | 
						
							| 28 | 25 26 27 | sylancl |  |-  ( ph -> ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) e. ( *Met ` ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) | 
						
							| 29 |  | df-ov |  |-  ( A ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) B ) = ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) | 
						
							| 30 | 15 | xpsfval |  |-  ( ( A e. X /\ B e. Y ) -> ( A ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) B ) = { <. (/) , A >. , <. 1o , B >. } ) | 
						
							| 31 | 11 12 30 | syl2anc |  |-  ( ph -> ( A ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) B ) = { <. (/) , A >. , <. 1o , B >. } ) | 
						
							| 32 | 29 31 | eqtr3id |  |-  ( ph -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) = { <. (/) , A >. , <. 1o , B >. } ) | 
						
							| 33 | 11 12 | opelxpd |  |-  ( ph -> <. A , B >. e. ( X X. Y ) ) | 
						
							| 34 |  | f1of |  |-  ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) -1-1-onto-> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) -> ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) --> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 35 | 20 34 | ax-mp |  |-  ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) --> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) | 
						
							| 36 | 35 | ffvelcdmi |  |-  ( <. A , B >. e. ( X X. Y ) -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 37 | 33 36 | syl |  |-  ( ph -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 38 | 32 37 | eqeltrrd |  |-  ( ph -> { <. (/) , A >. , <. 1o , B >. } e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 39 |  | df-ov |  |-  ( C ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) D ) = ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) | 
						
							| 40 | 15 | xpsfval |  |-  ( ( C e. X /\ D e. Y ) -> ( C ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) D ) = { <. (/) , C >. , <. 1o , D >. } ) | 
						
							| 41 | 13 14 40 | syl2anc |  |-  ( ph -> ( C ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) D ) = { <. (/) , C >. , <. 1o , D >. } ) | 
						
							| 42 | 39 41 | eqtr3id |  |-  ( ph -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) = { <. (/) , C >. , <. 1o , D >. } ) | 
						
							| 43 | 13 14 | opelxpd |  |-  ( ph -> <. C , D >. e. ( X X. Y ) ) | 
						
							| 44 | 35 | ffvelcdmi |  |-  ( <. C , D >. e. ( X X. Y ) -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 45 | 43 44 | syl |  |-  ( ph -> ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 46 | 42 45 | eqeltrrd |  |-  ( ph -> { <. (/) , C >. , <. 1o , D >. } e. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) | 
						
							| 47 | 18 19 22 23 24 6 28 38 46 | imasdsf1o |  |-  ( ph -> ( ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) P ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) ) = ( { <. (/) , A >. , <. 1o , B >. } ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) { <. (/) , C >. , <. 1o , D >. } ) ) | 
						
							| 48 | 38 46 | ovresd |  |-  ( ph -> ( { <. (/) , A >. , <. 1o , B >. } ( ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) |` ( ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) X. ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ) ) { <. (/) , C >. , <. 1o , D >. } ) = ( { <. (/) , A >. , <. 1o , B >. } ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) { <. (/) , C >. , <. 1o , D >. } ) ) | 
						
							| 49 | 47 48 | eqtrd |  |-  ( ph -> ( ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) P ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) ) = ( { <. (/) , A >. , <. 1o , B >. } ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) { <. (/) , C >. , <. 1o , D >. } ) ) | 
						
							| 50 |  | f1ocnvfv |  |-  ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) -1-1-onto-> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) /\ <. A , B >. e. ( X X. Y ) ) -> ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) = { <. (/) , A >. , <. 1o , B >. } -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) = <. A , B >. ) ) | 
						
							| 51 | 20 33 50 | sylancr |  |-  ( ph -> ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. A , B >. ) = { <. (/) , A >. , <. 1o , B >. } -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) = <. A , B >. ) ) | 
						
							| 52 | 32 51 | mpd |  |-  ( ph -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) = <. A , B >. ) | 
						
							| 53 |  | f1ocnvfv |  |-  ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) : ( X X. Y ) -1-1-onto-> ran ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) /\ <. C , D >. e. ( X X. Y ) ) -> ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) = { <. (/) , C >. , <. 1o , D >. } -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) = <. C , D >. ) ) | 
						
							| 54 | 20 43 53 | sylancr |  |-  ( ph -> ( ( ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` <. C , D >. ) = { <. (/) , C >. , <. 1o , D >. } -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) = <. C , D >. ) ) | 
						
							| 55 | 42 54 | mpd |  |-  ( ph -> ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) = <. C , D >. ) | 
						
							| 56 | 52 55 | oveq12d |  |-  ( ph -> ( ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , A >. , <. 1o , B >. } ) P ( `' ( x e. X , y e. Y |-> { <. (/) , x >. , <. 1o , y >. } ) ` { <. (/) , C >. , <. 1o , D >. } ) ) = ( <. A , B >. P <. C , D >. ) ) | 
						
							| 57 |  | eqid |  |-  ( Base ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) = ( Base ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) | 
						
							| 58 |  | fvexd |  |-  ( ph -> ( Scalar ` R ) e. _V ) | 
						
							| 59 |  | 2on |  |-  2o e. On | 
						
							| 60 | 59 | a1i |  |-  ( ph -> 2o e. On ) | 
						
							| 61 |  | fnpr2o |  |-  ( ( R e. V /\ S e. W ) -> { <. (/) , R >. , <. 1o , S >. } Fn 2o ) | 
						
							| 62 | 4 5 61 | syl2anc |  |-  ( ph -> { <. (/) , R >. , <. 1o , S >. } Fn 2o ) | 
						
							| 63 | 38 19 | eleqtrd |  |-  ( ph -> { <. (/) , A >. , <. 1o , B >. } e. ( Base ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) ) | 
						
							| 64 | 46 19 | eleqtrd |  |-  ( ph -> { <. (/) , C >. , <. 1o , D >. } e. ( Base ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) ) | 
						
							| 65 |  | eqid |  |-  ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) = ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) | 
						
							| 66 | 17 57 58 60 62 63 64 65 | prdsdsval |  |-  ( ph -> ( { <. (/) , A >. , <. 1o , B >. } ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) { <. (/) , C >. , <. 1o , D >. } ) = sup ( ( ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) u. { 0 } ) , RR* , < ) ) | 
						
							| 67 |  | df2o3 |  |-  2o = { (/) , 1o } | 
						
							| 68 | 67 | rexeqi |  |-  ( E. k e. 2o x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> E. k e. { (/) , 1o } x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) | 
						
							| 69 |  | 0ex |  |-  (/) e. _V | 
						
							| 70 |  | 1oex |  |-  1o e. _V | 
						
							| 71 |  | 2fveq3 |  |-  ( k = (/) -> ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) = ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ) | 
						
							| 72 |  | fveq2 |  |-  ( k = (/) -> ( { <. (/) , A >. , <. 1o , B >. } ` k ) = ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ) | 
						
							| 73 |  | fveq2 |  |-  ( k = (/) -> ( { <. (/) , C >. , <. 1o , D >. } ` k ) = ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) | 
						
							| 74 | 71 72 73 | oveq123d |  |-  ( k = (/) -> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) ) | 
						
							| 75 | 74 | eqeq2d |  |-  ( k = (/) -> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> x = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) ) ) | 
						
							| 76 |  | 2fveq3 |  |-  ( k = 1o -> ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) = ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ) | 
						
							| 77 |  | fveq2 |  |-  ( k = 1o -> ( { <. (/) , A >. , <. 1o , B >. } ` k ) = ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ) | 
						
							| 78 |  | fveq2 |  |-  ( k = 1o -> ( { <. (/) , C >. , <. 1o , D >. } ` k ) = ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) | 
						
							| 79 | 76 77 78 | oveq123d |  |-  ( k = 1o -> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) ) | 
						
							| 80 | 79 | eqeq2d |  |-  ( k = 1o -> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> x = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) ) ) | 
						
							| 81 | 69 70 75 80 | rexpr |  |-  ( E. k e. { (/) , 1o } x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) \/ x = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) ) ) | 
						
							| 82 | 68 81 | bitri |  |-  ( E. k e. 2o x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) \/ x = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) ) ) | 
						
							| 83 |  | fvpr0o |  |-  ( R e. V -> ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) = R ) | 
						
							| 84 | 4 83 | syl |  |-  ( ph -> ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) = R ) | 
						
							| 85 | 84 | fveq2d |  |-  ( ph -> ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) = ( dist ` R ) ) | 
						
							| 86 |  | fvpr0o |  |-  ( A e. X -> ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) = A ) | 
						
							| 87 | 11 86 | syl |  |-  ( ph -> ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) = A ) | 
						
							| 88 |  | fvpr0o |  |-  ( C e. X -> ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) = C ) | 
						
							| 89 | 13 88 | syl |  |-  ( ph -> ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) = C ) | 
						
							| 90 | 85 87 89 | oveq123d |  |-  ( ph -> ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) = ( A ( dist ` R ) C ) ) | 
						
							| 91 | 7 | oveqi |  |-  ( A M C ) = ( A ( ( dist ` R ) |` ( X X. X ) ) C ) | 
						
							| 92 | 11 13 | ovresd |  |-  ( ph -> ( A ( ( dist ` R ) |` ( X X. X ) ) C ) = ( A ( dist ` R ) C ) ) | 
						
							| 93 | 91 92 | eqtrid |  |-  ( ph -> ( A M C ) = ( A ( dist ` R ) C ) ) | 
						
							| 94 | 90 93 | eqtr4d |  |-  ( ph -> ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) = ( A M C ) ) | 
						
							| 95 | 94 | eqeq2d |  |-  ( ph -> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) <-> x = ( A M C ) ) ) | 
						
							| 96 |  | fvpr1o |  |-  ( S e. W -> ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) = S ) | 
						
							| 97 | 5 96 | syl |  |-  ( ph -> ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) = S ) | 
						
							| 98 | 97 | fveq2d |  |-  ( ph -> ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) = ( dist ` S ) ) | 
						
							| 99 |  | fvpr1o |  |-  ( B e. Y -> ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) = B ) | 
						
							| 100 | 12 99 | syl |  |-  ( ph -> ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) = B ) | 
						
							| 101 |  | fvpr1o |  |-  ( D e. Y -> ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) = D ) | 
						
							| 102 | 14 101 | syl |  |-  ( ph -> ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) = D ) | 
						
							| 103 | 98 100 102 | oveq123d |  |-  ( ph -> ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) = ( B ( dist ` S ) D ) ) | 
						
							| 104 | 8 | oveqi |  |-  ( B N D ) = ( B ( ( dist ` S ) |` ( Y X. Y ) ) D ) | 
						
							| 105 | 12 14 | ovresd |  |-  ( ph -> ( B ( ( dist ` S ) |` ( Y X. Y ) ) D ) = ( B ( dist ` S ) D ) ) | 
						
							| 106 | 104 105 | eqtrid |  |-  ( ph -> ( B N D ) = ( B ( dist ` S ) D ) ) | 
						
							| 107 | 103 106 | eqtr4d |  |-  ( ph -> ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) = ( B N D ) ) | 
						
							| 108 | 107 | eqeq2d |  |-  ( ph -> ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) <-> x = ( B N D ) ) ) | 
						
							| 109 | 95 108 | orbi12d |  |-  ( ph -> ( ( x = ( ( { <. (/) , A >. , <. 1o , B >. } ` (/) ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` (/) ) ) ( { <. (/) , C >. , <. 1o , D >. } ` (/) ) ) \/ x = ( ( { <. (/) , A >. , <. 1o , B >. } ` 1o ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` 1o ) ) ( { <. (/) , C >. , <. 1o , D >. } ` 1o ) ) ) <-> ( x = ( A M C ) \/ x = ( B N D ) ) ) ) | 
						
							| 110 | 82 109 | bitrid |  |-  ( ph -> ( E. k e. 2o x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) <-> ( x = ( A M C ) \/ x = ( B N D ) ) ) ) | 
						
							| 111 |  | eqid |  |-  ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) = ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) | 
						
							| 112 | 111 | elrnmpt |  |-  ( x e. _V -> ( x e. ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) <-> E. k e. 2o x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) ) | 
						
							| 113 | 112 | elv |  |-  ( x e. ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) <-> E. k e. 2o x = ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) | 
						
							| 114 |  | vex |  |-  x e. _V | 
						
							| 115 | 114 | elpr |  |-  ( x e. { ( A M C ) , ( B N D ) } <-> ( x = ( A M C ) \/ x = ( B N D ) ) ) | 
						
							| 116 | 110 113 115 | 3bitr4g |  |-  ( ph -> ( x e. ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) <-> x e. { ( A M C ) , ( B N D ) } ) ) | 
						
							| 117 | 116 | eqrdv |  |-  ( ph -> ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) = { ( A M C ) , ( B N D ) } ) | 
						
							| 118 | 117 | uneq1d |  |-  ( ph -> ( ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) u. { 0 } ) = ( { ( A M C ) , ( B N D ) } u. { 0 } ) ) | 
						
							| 119 |  | uncom |  |-  ( { ( A M C ) , ( B N D ) } u. { 0 } ) = ( { 0 } u. { ( A M C ) , ( B N D ) } ) | 
						
							| 120 | 118 119 | eqtrdi |  |-  ( ph -> ( ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) u. { 0 } ) = ( { 0 } u. { ( A M C ) , ( B N D ) } ) ) | 
						
							| 121 | 120 | supeq1d |  |-  ( ph -> sup ( ( ran ( k e. 2o |-> ( ( { <. (/) , A >. , <. 1o , B >. } ` k ) ( dist ` ( { <. (/) , R >. , <. 1o , S >. } ` k ) ) ( { <. (/) , C >. , <. 1o , D >. } ` k ) ) ) u. { 0 } ) , RR* , < ) = sup ( ( { 0 } u. { ( A M C ) , ( B N D ) } ) , RR* , < ) ) | 
						
							| 122 |  | 0xr |  |-  0 e. RR* | 
						
							| 123 | 122 | a1i |  |-  ( ph -> 0 e. RR* ) | 
						
							| 124 | 123 | snssd |  |-  ( ph -> { 0 } C_ RR* ) | 
						
							| 125 |  | xmetcl |  |-  ( ( M e. ( *Met ` X ) /\ A e. X /\ C e. X ) -> ( A M C ) e. RR* ) | 
						
							| 126 | 9 11 13 125 | syl3anc |  |-  ( ph -> ( A M C ) e. RR* ) | 
						
							| 127 |  | xmetcl |  |-  ( ( N e. ( *Met ` Y ) /\ B e. Y /\ D e. Y ) -> ( B N D ) e. RR* ) | 
						
							| 128 | 10 12 14 127 | syl3anc |  |-  ( ph -> ( B N D ) e. RR* ) | 
						
							| 129 | 126 128 | prssd |  |-  ( ph -> { ( A M C ) , ( B N D ) } C_ RR* ) | 
						
							| 130 |  | xrltso |  |-  < Or RR* | 
						
							| 131 |  | supsn |  |-  ( ( < Or RR* /\ 0 e. RR* ) -> sup ( { 0 } , RR* , < ) = 0 ) | 
						
							| 132 | 130 122 131 | mp2an |  |-  sup ( { 0 } , RR* , < ) = 0 | 
						
							| 133 |  | supxrcl |  |-  ( { ( A M C ) , ( B N D ) } C_ RR* -> sup ( { ( A M C ) , ( B N D ) } , RR* , < ) e. RR* ) | 
						
							| 134 | 129 133 | syl |  |-  ( ph -> sup ( { ( A M C ) , ( B N D ) } , RR* , < ) e. RR* ) | 
						
							| 135 |  | xmetge0 |  |-  ( ( M e. ( *Met ` X ) /\ A e. X /\ C e. X ) -> 0 <_ ( A M C ) ) | 
						
							| 136 | 9 11 13 135 | syl3anc |  |-  ( ph -> 0 <_ ( A M C ) ) | 
						
							| 137 |  | ovex |  |-  ( A M C ) e. _V | 
						
							| 138 | 137 | prid1 |  |-  ( A M C ) e. { ( A M C ) , ( B N D ) } | 
						
							| 139 |  | supxrub |  |-  ( ( { ( A M C ) , ( B N D ) } C_ RR* /\ ( A M C ) e. { ( A M C ) , ( B N D ) } ) -> ( A M C ) <_ sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 140 | 129 138 139 | sylancl |  |-  ( ph -> ( A M C ) <_ sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 141 | 123 126 134 136 140 | xrletrd |  |-  ( ph -> 0 <_ sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 142 | 132 141 | eqbrtrid |  |-  ( ph -> sup ( { 0 } , RR* , < ) <_ sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 143 |  | supxrun |  |-  ( ( { 0 } C_ RR* /\ { ( A M C ) , ( B N D ) } C_ RR* /\ sup ( { 0 } , RR* , < ) <_ sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) -> sup ( ( { 0 } u. { ( A M C ) , ( B N D ) } ) , RR* , < ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 144 | 124 129 142 143 | syl3anc |  |-  ( ph -> sup ( ( { 0 } u. { ( A M C ) , ( B N D ) } ) , RR* , < ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 145 | 66 121 144 | 3eqtrd |  |-  ( ph -> ( { <. (/) , A >. , <. 1o , B >. } ( dist ` ( ( Scalar ` R ) Xs_ { <. (/) , R >. , <. 1o , S >. } ) ) { <. (/) , C >. , <. 1o , D >. } ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 146 | 49 56 145 | 3eqtr3d |  |-  ( ph -> ( <. A , B >. P <. C , D >. ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) |