| Step | Hyp | Ref | Expression | 
						
							| 1 |  | h1de2.1 |  |-  A e. ~H | 
						
							| 2 |  | h1de2.2 |  |-  B e. ~H | 
						
							| 3 | 2 2 | hicli |  |-  ( B .ih B ) e. CC | 
						
							| 4 | 3 1 | hvmulcli |  |-  ( ( B .ih B ) .h A ) e. ~H | 
						
							| 5 | 1 2 | hicli |  |-  ( A .ih B ) e. CC | 
						
							| 6 | 5 2 | hvmulcli |  |-  ( ( A .ih B ) .h B ) e. ~H | 
						
							| 7 |  | his2sub |  |-  ( ( ( ( B .ih B ) .h A ) e. ~H /\ ( ( A .ih B ) .h B ) e. ~H /\ A e. ~H ) -> ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = ( ( ( ( B .ih B ) .h A ) .ih A ) - ( ( ( A .ih B ) .h B ) .ih A ) ) ) | 
						
							| 8 | 4 6 1 7 | mp3an |  |-  ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = ( ( ( ( B .ih B ) .h A ) .ih A ) - ( ( ( A .ih B ) .h B ) .ih A ) ) | 
						
							| 9 |  | ax-his3 |  |-  ( ( ( B .ih B ) e. CC /\ A e. ~H /\ A e. ~H ) -> ( ( ( B .ih B ) .h A ) .ih A ) = ( ( B .ih B ) x. ( A .ih A ) ) ) | 
						
							| 10 | 3 1 1 9 | mp3an |  |-  ( ( ( B .ih B ) .h A ) .ih A ) = ( ( B .ih B ) x. ( A .ih A ) ) | 
						
							| 11 | 1 1 | hicli |  |-  ( A .ih A ) e. CC | 
						
							| 12 | 3 11 | mulcomi |  |-  ( ( B .ih B ) x. ( A .ih A ) ) = ( ( A .ih A ) x. ( B .ih B ) ) | 
						
							| 13 | 10 12 | eqtri |  |-  ( ( ( B .ih B ) .h A ) .ih A ) = ( ( A .ih A ) x. ( B .ih B ) ) | 
						
							| 14 |  | ax-his3 |  |-  ( ( ( A .ih B ) e. CC /\ B e. ~H /\ A e. ~H ) -> ( ( ( A .ih B ) .h B ) .ih A ) = ( ( A .ih B ) x. ( B .ih A ) ) ) | 
						
							| 15 | 5 2 1 14 | mp3an |  |-  ( ( ( A .ih B ) .h B ) .ih A ) = ( ( A .ih B ) x. ( B .ih A ) ) | 
						
							| 16 | 13 15 | oveq12i |  |-  ( ( ( ( B .ih B ) .h A ) .ih A ) - ( ( ( A .ih B ) .h B ) .ih A ) ) = ( ( ( A .ih A ) x. ( B .ih B ) ) - ( ( A .ih B ) x. ( B .ih A ) ) ) | 
						
							| 17 | 8 16 | eqtr2i |  |-  ( ( ( A .ih A ) x. ( B .ih B ) ) - ( ( A .ih B ) x. ( B .ih A ) ) ) = ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) | 
						
							| 18 |  | his2sub |  |-  ( ( ( ( B .ih B ) .h A ) e. ~H /\ ( ( A .ih B ) .h B ) e. ~H /\ B e. ~H ) -> ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = ( ( ( ( B .ih B ) .h A ) .ih B ) - ( ( ( A .ih B ) .h B ) .ih B ) ) ) | 
						
							| 19 | 4 6 2 18 | mp3an |  |-  ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = ( ( ( ( B .ih B ) .h A ) .ih B ) - ( ( ( A .ih B ) .h B ) .ih B ) ) | 
						
							| 20 | 3 5 | mulcomi |  |-  ( ( B .ih B ) x. ( A .ih B ) ) = ( ( A .ih B ) x. ( B .ih B ) ) | 
						
							| 21 |  | ax-his3 |  |-  ( ( ( B .ih B ) e. CC /\ A e. ~H /\ B e. ~H ) -> ( ( ( B .ih B ) .h A ) .ih B ) = ( ( B .ih B ) x. ( A .ih B ) ) ) | 
						
							| 22 | 3 1 2 21 | mp3an |  |-  ( ( ( B .ih B ) .h A ) .ih B ) = ( ( B .ih B ) x. ( A .ih B ) ) | 
						
							| 23 |  | ax-his3 |  |-  ( ( ( A .ih B ) e. CC /\ B e. ~H /\ B e. ~H ) -> ( ( ( A .ih B ) .h B ) .ih B ) = ( ( A .ih B ) x. ( B .ih B ) ) ) | 
						
							| 24 | 5 2 2 23 | mp3an |  |-  ( ( ( A .ih B ) .h B ) .ih B ) = ( ( A .ih B ) x. ( B .ih B ) ) | 
						
							| 25 | 20 22 24 | 3eqtr4i |  |-  ( ( ( B .ih B ) .h A ) .ih B ) = ( ( ( A .ih B ) .h B ) .ih B ) | 
						
							| 26 | 4 2 | hicli |  |-  ( ( ( B .ih B ) .h A ) .ih B ) e. CC | 
						
							| 27 | 6 2 | hicli |  |-  ( ( ( A .ih B ) .h B ) .ih B ) e. CC | 
						
							| 28 | 26 27 | subeq0i |  |-  ( ( ( ( ( B .ih B ) .h A ) .ih B ) - ( ( ( A .ih B ) .h B ) .ih B ) ) = 0 <-> ( ( ( B .ih B ) .h A ) .ih B ) = ( ( ( A .ih B ) .h B ) .ih B ) ) | 
						
							| 29 | 25 28 | mpbir |  |-  ( ( ( ( B .ih B ) .h A ) .ih B ) - ( ( ( A .ih B ) .h B ) .ih B ) ) = 0 | 
						
							| 30 | 19 29 | eqtri |  |-  ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = 0 | 
						
							| 31 | 2 | h1dei |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) <-> ( A e. ~H /\ A. x e. ~H ( ( B .ih x ) = 0 -> ( A .ih x ) = 0 ) ) ) | 
						
							| 32 | 1 31 | mpbiran |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) <-> A. x e. ~H ( ( B .ih x ) = 0 -> ( A .ih x ) = 0 ) ) | 
						
							| 33 | 4 6 | hvsubcli |  |-  ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) e. ~H | 
						
							| 34 |  | oveq2 |  |-  ( x = ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) -> ( B .ih x ) = ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) ) | 
						
							| 35 | 34 | eqeq1d |  |-  ( x = ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) -> ( ( B .ih x ) = 0 <-> ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 36 |  | oveq2 |  |-  ( x = ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) -> ( A .ih x ) = ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) ) | 
						
							| 37 | 36 | eqeq1d |  |-  ( x = ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) -> ( ( A .ih x ) = 0 <-> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 38 | 35 37 | imbi12d |  |-  ( x = ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) -> ( ( ( B .ih x ) = 0 -> ( A .ih x ) = 0 ) <-> ( ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 -> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) ) | 
						
							| 39 | 38 | rspcv |  |-  ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) e. ~H -> ( A. x e. ~H ( ( B .ih x ) = 0 -> ( A .ih x ) = 0 ) -> ( ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 -> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) ) | 
						
							| 40 | 33 39 | ax-mp |  |-  ( A. x e. ~H ( ( B .ih x ) = 0 -> ( A .ih x ) = 0 ) -> ( ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 -> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 41 | 32 40 | sylbi |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 -> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 42 |  | orthcom |  |-  ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) e. ~H /\ B e. ~H ) -> ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = 0 <-> ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 43 | 33 2 42 | mp2an |  |-  ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = 0 <-> ( B .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) | 
						
							| 44 |  | orthcom |  |-  ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) e. ~H /\ A e. ~H ) -> ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = 0 <-> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) ) | 
						
							| 45 | 33 1 44 | mp2an |  |-  ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = 0 <-> ( A .ih ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) ) = 0 ) | 
						
							| 46 | 41 43 45 | 3imtr4g |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih B ) = 0 -> ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = 0 ) ) | 
						
							| 47 | 30 46 | mpi |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( ( ( B .ih B ) .h A ) -h ( ( A .ih B ) .h B ) ) .ih A ) = 0 ) | 
						
							| 48 | 17 47 | eqtrid |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( ( A .ih A ) x. ( B .ih B ) ) - ( ( A .ih B ) x. ( B .ih A ) ) ) = 0 ) | 
						
							| 49 | 11 3 | mulcli |  |-  ( ( A .ih A ) x. ( B .ih B ) ) e. CC | 
						
							| 50 | 2 1 | hicli |  |-  ( B .ih A ) e. CC | 
						
							| 51 | 5 50 | mulcli |  |-  ( ( A .ih B ) x. ( B .ih A ) ) e. CC | 
						
							| 52 | 49 51 | subeq0i |  |-  ( ( ( ( A .ih A ) x. ( B .ih B ) ) - ( ( A .ih B ) x. ( B .ih A ) ) ) = 0 <-> ( ( A .ih A ) x. ( B .ih B ) ) = ( ( A .ih B ) x. ( B .ih A ) ) ) | 
						
							| 53 | 48 52 | sylib |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( A .ih A ) x. ( B .ih B ) ) = ( ( A .ih B ) x. ( B .ih A ) ) ) | 
						
							| 54 | 53 | eqcomd |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( A .ih B ) x. ( B .ih A ) ) = ( ( A .ih A ) x. ( B .ih B ) ) ) | 
						
							| 55 | 1 2 | bcseqi |  |-  ( ( ( A .ih B ) x. ( B .ih A ) ) = ( ( A .ih A ) x. ( B .ih B ) ) <-> ( ( B .ih B ) .h A ) = ( ( A .ih B ) .h B ) ) | 
						
							| 56 | 54 55 | sylib |  |-  ( A e. ( _|_ ` ( _|_ ` { B } ) ) -> ( ( B .ih B ) .h A ) = ( ( A .ih B ) .h B ) ) |