| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tmsxps.p |  |-  P = ( dist ` ( ( toMetSp ` M ) Xs. ( toMetSp ` N ) ) ) | 
						
							| 2 |  | tmsxps.1 |  |-  ( ph -> M e. ( *Met ` X ) ) | 
						
							| 3 |  | tmsxps.2 |  |-  ( ph -> N e. ( *Met ` Y ) ) | 
						
							| 4 |  | tmsxpsval.a |  |-  ( ph -> A e. X ) | 
						
							| 5 |  | tmsxpsval.b |  |-  ( ph -> B e. Y ) | 
						
							| 6 |  | tmsxpsval.c |  |-  ( ph -> C e. X ) | 
						
							| 7 |  | tmsxpsval.d |  |-  ( ph -> D e. Y ) | 
						
							| 8 |  | eqid |  |-  ( ( toMetSp ` M ) Xs. ( toMetSp ` N ) ) = ( ( toMetSp ` M ) Xs. ( toMetSp ` N ) ) | 
						
							| 9 |  | eqid |  |-  ( Base ` ( toMetSp ` M ) ) = ( Base ` ( toMetSp ` M ) ) | 
						
							| 10 |  | eqid |  |-  ( Base ` ( toMetSp ` N ) ) = ( Base ` ( toMetSp ` N ) ) | 
						
							| 11 |  | eqid |  |-  ( toMetSp ` M ) = ( toMetSp ` M ) | 
						
							| 12 | 11 | tmsxms |  |-  ( M e. ( *Met ` X ) -> ( toMetSp ` M ) e. *MetSp ) | 
						
							| 13 | 2 12 | syl |  |-  ( ph -> ( toMetSp ` M ) e. *MetSp ) | 
						
							| 14 |  | eqid |  |-  ( toMetSp ` N ) = ( toMetSp ` N ) | 
						
							| 15 | 14 | tmsxms |  |-  ( N e. ( *Met ` Y ) -> ( toMetSp ` N ) e. *MetSp ) | 
						
							| 16 | 3 15 | syl |  |-  ( ph -> ( toMetSp ` N ) e. *MetSp ) | 
						
							| 17 |  | eqid |  |-  ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) = ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) | 
						
							| 18 |  | eqid |  |-  ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) = ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) | 
						
							| 19 | 11 | tmsds |  |-  ( M e. ( *Met ` X ) -> M = ( dist ` ( toMetSp ` M ) ) ) | 
						
							| 20 | 2 19 | syl |  |-  ( ph -> M = ( dist ` ( toMetSp ` M ) ) ) | 
						
							| 21 | 11 | tmsbas |  |-  ( M e. ( *Met ` X ) -> X = ( Base ` ( toMetSp ` M ) ) ) | 
						
							| 22 | 2 21 | syl |  |-  ( ph -> X = ( Base ` ( toMetSp ` M ) ) ) | 
						
							| 23 | 22 | fveq2d |  |-  ( ph -> ( *Met ` X ) = ( *Met ` ( Base ` ( toMetSp ` M ) ) ) ) | 
						
							| 24 | 2 20 23 | 3eltr3d |  |-  ( ph -> ( dist ` ( toMetSp ` M ) ) e. ( *Met ` ( Base ` ( toMetSp ` M ) ) ) ) | 
						
							| 25 |  | ssid |  |-  ( Base ` ( toMetSp ` M ) ) C_ ( Base ` ( toMetSp ` M ) ) | 
						
							| 26 |  | xmetres2 |  |-  ( ( ( dist ` ( toMetSp ` M ) ) e. ( *Met ` ( Base ` ( toMetSp ` M ) ) ) /\ ( Base ` ( toMetSp ` M ) ) C_ ( Base ` ( toMetSp ` M ) ) ) -> ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) e. ( *Met ` ( Base ` ( toMetSp ` M ) ) ) ) | 
						
							| 27 | 24 25 26 | sylancl |  |-  ( ph -> ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) e. ( *Met ` ( Base ` ( toMetSp ` M ) ) ) ) | 
						
							| 28 | 14 | tmsds |  |-  ( N e. ( *Met ` Y ) -> N = ( dist ` ( toMetSp ` N ) ) ) | 
						
							| 29 | 3 28 | syl |  |-  ( ph -> N = ( dist ` ( toMetSp ` N ) ) ) | 
						
							| 30 | 14 | tmsbas |  |-  ( N e. ( *Met ` Y ) -> Y = ( Base ` ( toMetSp ` N ) ) ) | 
						
							| 31 | 3 30 | syl |  |-  ( ph -> Y = ( Base ` ( toMetSp ` N ) ) ) | 
						
							| 32 | 31 | fveq2d |  |-  ( ph -> ( *Met ` Y ) = ( *Met ` ( Base ` ( toMetSp ` N ) ) ) ) | 
						
							| 33 | 3 29 32 | 3eltr3d |  |-  ( ph -> ( dist ` ( toMetSp ` N ) ) e. ( *Met ` ( Base ` ( toMetSp ` N ) ) ) ) | 
						
							| 34 |  | ssid |  |-  ( Base ` ( toMetSp ` N ) ) C_ ( Base ` ( toMetSp ` N ) ) | 
						
							| 35 |  | xmetres2 |  |-  ( ( ( dist ` ( toMetSp ` N ) ) e. ( *Met ` ( Base ` ( toMetSp ` N ) ) ) /\ ( Base ` ( toMetSp ` N ) ) C_ ( Base ` ( toMetSp ` N ) ) ) -> ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) e. ( *Met ` ( Base ` ( toMetSp ` N ) ) ) ) | 
						
							| 36 | 33 34 35 | sylancl |  |-  ( ph -> ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) e. ( *Met ` ( Base ` ( toMetSp ` N ) ) ) ) | 
						
							| 37 | 4 22 | eleqtrd |  |-  ( ph -> A e. ( Base ` ( toMetSp ` M ) ) ) | 
						
							| 38 | 5 31 | eleqtrd |  |-  ( ph -> B e. ( Base ` ( toMetSp ` N ) ) ) | 
						
							| 39 | 6 22 | eleqtrd |  |-  ( ph -> C e. ( Base ` ( toMetSp ` M ) ) ) | 
						
							| 40 | 7 31 | eleqtrd |  |-  ( ph -> D e. ( Base ` ( toMetSp ` N ) ) ) | 
						
							| 41 | 8 9 10 13 16 1 17 18 27 36 37 38 39 40 | xpsdsval |  |-  ( ph -> ( <. A , B >. P <. C , D >. ) = sup ( { ( A ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) C ) , ( B ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) D ) } , RR* , < ) ) | 
						
							| 42 | 37 39 | ovresd |  |-  ( ph -> ( A ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) C ) = ( A ( dist ` ( toMetSp ` M ) ) C ) ) | 
						
							| 43 | 20 | oveqd |  |-  ( ph -> ( A M C ) = ( A ( dist ` ( toMetSp ` M ) ) C ) ) | 
						
							| 44 | 42 43 | eqtr4d |  |-  ( ph -> ( A ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) C ) = ( A M C ) ) | 
						
							| 45 | 38 40 | ovresd |  |-  ( ph -> ( B ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) D ) = ( B ( dist ` ( toMetSp ` N ) ) D ) ) | 
						
							| 46 | 29 | oveqd |  |-  ( ph -> ( B N D ) = ( B ( dist ` ( toMetSp ` N ) ) D ) ) | 
						
							| 47 | 45 46 | eqtr4d |  |-  ( ph -> ( B ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) D ) = ( B N D ) ) | 
						
							| 48 | 44 47 | preq12d |  |-  ( ph -> { ( A ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) C ) , ( B ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) D ) } = { ( A M C ) , ( B N D ) } ) | 
						
							| 49 | 48 | supeq1d |  |-  ( ph -> sup ( { ( A ( ( dist ` ( toMetSp ` M ) ) |` ( ( Base ` ( toMetSp ` M ) ) X. ( Base ` ( toMetSp ` M ) ) ) ) C ) , ( B ( ( dist ` ( toMetSp ` N ) ) |` ( ( Base ` ( toMetSp ` N ) ) X. ( Base ` ( toMetSp ` N ) ) ) ) D ) } , RR* , < ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) | 
						
							| 50 | 41 49 | eqtrd |  |-  ( ph -> ( <. A , B >. P <. C , D >. ) = sup ( { ( A M C ) , ( B N D ) } , RR* , < ) ) |