| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pjidm.1 |  |-  H e. CH | 
						
							| 2 |  | pjidm.2 |  |-  A e. ~H | 
						
							| 3 |  | pjsslem.1 |  |-  G e. CH | 
						
							| 4 | 3 2 | pjclii |  |-  ( ( projh ` G ) ` A ) e. G | 
						
							| 5 | 1 2 | pjclii |  |-  ( ( projh ` H ) ` A ) e. H | 
						
							| 6 |  | ssel |  |-  ( H C_ G -> ( ( ( projh ` H ) ` A ) e. H -> ( ( projh ` H ) ` A ) e. G ) ) | 
						
							| 7 | 5 6 | mpi |  |-  ( H C_ G -> ( ( projh ` H ) ` A ) e. G ) | 
						
							| 8 | 3 | chshii |  |-  G e. SH | 
						
							| 9 |  | shsubcl |  |-  ( ( G e. SH /\ ( ( projh ` G ) ` A ) e. G /\ ( ( projh ` H ) ` A ) e. G ) -> ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G ) | 
						
							| 10 | 8 9 | mp3an1 |  |-  ( ( ( ( projh ` G ) ` A ) e. G /\ ( ( projh ` H ) ` A ) e. G ) -> ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G ) | 
						
							| 11 | 4 7 10 | sylancr |  |-  ( H C_ G -> ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G ) | 
						
							| 12 | 1 2 3 | pjsslem |  |-  ( ( ( projh ` ( _|_ ` H ) ) ` A ) -h ( ( projh ` ( _|_ ` G ) ) ` A ) ) = ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) | 
						
							| 13 | 1 3 | chsscon3i |  |-  ( H C_ G <-> ( _|_ ` G ) C_ ( _|_ ` H ) ) | 
						
							| 14 | 1 | choccli |  |-  ( _|_ ` H ) e. CH | 
						
							| 15 | 14 2 | pjclii |  |-  ( ( projh ` ( _|_ ` H ) ) ` A ) e. ( _|_ ` H ) | 
						
							| 16 | 3 | choccli |  |-  ( _|_ ` G ) e. CH | 
						
							| 17 | 16 2 | pjclii |  |-  ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` G ) | 
						
							| 18 |  | ssel |  |-  ( ( _|_ ` G ) C_ ( _|_ ` H ) -> ( ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` G ) -> ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` H ) ) ) | 
						
							| 19 | 17 18 | mpi |  |-  ( ( _|_ ` G ) C_ ( _|_ ` H ) -> ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` H ) ) | 
						
							| 20 | 14 | chshii |  |-  ( _|_ ` H ) e. SH | 
						
							| 21 |  | shsubcl |  |-  ( ( ( _|_ ` H ) e. SH /\ ( ( projh ` ( _|_ ` H ) ) ` A ) e. ( _|_ ` H ) /\ ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` H ) ) -> ( ( ( projh ` ( _|_ ` H ) ) ` A ) -h ( ( projh ` ( _|_ ` G ) ) ` A ) ) e. ( _|_ ` H ) ) | 
						
							| 22 | 20 21 | mp3an1 |  |-  ( ( ( ( projh ` ( _|_ ` H ) ) ` A ) e. ( _|_ ` H ) /\ ( ( projh ` ( _|_ ` G ) ) ` A ) e. ( _|_ ` H ) ) -> ( ( ( projh ` ( _|_ ` H ) ) ` A ) -h ( ( projh ` ( _|_ ` G ) ) ` A ) ) e. ( _|_ ` H ) ) | 
						
							| 23 | 15 19 22 | sylancr |  |-  ( ( _|_ ` G ) C_ ( _|_ ` H ) -> ( ( ( projh ` ( _|_ ` H ) ) ` A ) -h ( ( projh ` ( _|_ ` G ) ) ` A ) ) e. ( _|_ ` H ) ) | 
						
							| 24 | 13 23 | sylbi |  |-  ( H C_ G -> ( ( ( projh ` ( _|_ ` H ) ) ` A ) -h ( ( projh ` ( _|_ ` G ) ) ` A ) ) e. ( _|_ ` H ) ) | 
						
							| 25 | 12 24 | eqeltrrid |  |-  ( H C_ G -> ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( _|_ ` H ) ) | 
						
							| 26 | 11 25 | jca |  |-  ( H C_ G -> ( ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G /\ ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( _|_ ` H ) ) ) | 
						
							| 27 |  | elin |  |-  ( ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( G i^i ( _|_ ` H ) ) <-> ( ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G /\ ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( _|_ ` H ) ) ) | 
						
							| 28 | 3 14 | chincli |  |-  ( G i^i ( _|_ ` H ) ) e. CH | 
						
							| 29 | 3 2 | pjhclii |  |-  ( ( projh ` G ) ` A ) e. ~H | 
						
							| 30 | 1 2 | pjhclii |  |-  ( ( projh ` H ) ` A ) e. ~H | 
						
							| 31 | 29 30 | hvsubcli |  |-  ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ~H | 
						
							| 32 | 28 31 | pjchi |  |-  ( ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( G i^i ( _|_ ` H ) ) <-> ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) = ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) | 
						
							| 33 | 27 32 | bitr3i |  |-  ( ( ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. G /\ ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) e. ( _|_ ` H ) ) <-> ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) = ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) | 
						
							| 34 | 26 33 | sylib |  |-  ( H C_ G -> ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) = ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) | 
						
							| 35 | 28 29 30 | pjsubii |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) = ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) -h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) | 
						
							| 36 | 28 29 | pjhclii |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) e. ~H | 
						
							| 37 | 28 30 | pjhclii |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) e. ~H | 
						
							| 38 | 36 37 | hvsubvali |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) -h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) = ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) +h ( -u 1 .h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) ) | 
						
							| 39 |  | inss1 |  |-  ( G i^i ( _|_ ` H ) ) C_ G | 
						
							| 40 | 28 2 3 | pjss2i |  |-  ( ( G i^i ( _|_ ` H ) ) C_ G -> ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) ) | 
						
							| 41 | 39 40 | ax-mp |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) | 
						
							| 42 | 1 | chshii |  |-  H e. SH | 
						
							| 43 |  | shococss |  |-  ( H e. SH -> H C_ ( _|_ ` ( _|_ ` H ) ) ) | 
						
							| 44 | 42 43 | ax-mp |  |-  H C_ ( _|_ ` ( _|_ ` H ) ) | 
						
							| 45 |  | inss2 |  |-  ( G i^i ( _|_ ` H ) ) C_ ( _|_ ` H ) | 
						
							| 46 | 28 14 | chsscon3i |  |-  ( ( G i^i ( _|_ ` H ) ) C_ ( _|_ ` H ) <-> ( _|_ ` ( _|_ ` H ) ) C_ ( _|_ ` ( G i^i ( _|_ ` H ) ) ) ) | 
						
							| 47 | 45 46 | mpbi |  |-  ( _|_ ` ( _|_ ` H ) ) C_ ( _|_ ` ( G i^i ( _|_ ` H ) ) ) | 
						
							| 48 | 44 47 | sstri |  |-  H C_ ( _|_ ` ( G i^i ( _|_ ` H ) ) ) | 
						
							| 49 | 48 5 | sselii |  |-  ( ( projh ` H ) ` A ) e. ( _|_ ` ( G i^i ( _|_ ` H ) ) ) | 
						
							| 50 | 28 30 | pjoc2i |  |-  ( ( ( projh ` H ) ` A ) e. ( _|_ ` ( G i^i ( _|_ ` H ) ) ) <-> ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) = 0h ) | 
						
							| 51 | 49 50 | mpbi |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) = 0h | 
						
							| 52 | 51 | oveq2i |  |-  ( -u 1 .h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) = ( -u 1 .h 0h ) | 
						
							| 53 |  | neg1cn |  |-  -u 1 e. CC | 
						
							| 54 |  | hvmul0 |  |-  ( -u 1 e. CC -> ( -u 1 .h 0h ) = 0h ) | 
						
							| 55 | 53 54 | ax-mp |  |-  ( -u 1 .h 0h ) = 0h | 
						
							| 56 | 52 55 | eqtri |  |-  ( -u 1 .h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) = 0h | 
						
							| 57 | 41 56 | oveq12i |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) +h ( -u 1 .h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) ) = ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) +h 0h ) | 
						
							| 58 | 28 2 | pjhclii |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) e. ~H | 
						
							| 59 |  | ax-hvaddid |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) e. ~H -> ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) +h 0h ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) ) | 
						
							| 60 | 58 59 | ax-mp |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) +h 0h ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) | 
						
							| 61 | 57 60 | eqtri |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) +h ( -u 1 .h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) | 
						
							| 62 | 38 61 | eqtri |  |-  ( ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` G ) ` A ) ) -h ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( projh ` H ) ` A ) ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) | 
						
							| 63 | 35 62 | eqtri |  |-  ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) | 
						
							| 64 | 34 63 | eqtr3di |  |-  ( H C_ G -> ( ( ( projh ` G ) ` A ) -h ( ( projh ` H ) ` A ) ) = ( ( projh ` ( G i^i ( _|_ ` H ) ) ) ` A ) ) |