| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdh.q |  |-  Q = ( 0g ` C ) | 
						
							| 2 |  | mapdh.i |  |-  I = ( x e. _V |-> if ( ( 2nd ` x ) = .0. , Q , ( iota_ h e. D ( ( M ` ( N ` { ( 2nd ` x ) } ) ) = ( J ` { h } ) /\ ( M ` ( N ` { ( ( 1st ` ( 1st ` x ) ) .- ( 2nd ` x ) ) } ) ) = ( J ` { ( ( 2nd ` ( 1st ` x ) ) R h ) } ) ) ) ) ) | 
						
							| 3 |  | mapdh.h |  |-  H = ( LHyp ` K ) | 
						
							| 4 |  | mapdh.m |  |-  M = ( ( mapd ` K ) ` W ) | 
						
							| 5 |  | mapdh.u |  |-  U = ( ( DVecH ` K ) ` W ) | 
						
							| 6 |  | mapdh.v |  |-  V = ( Base ` U ) | 
						
							| 7 |  | mapdh.s |  |-  .- = ( -g ` U ) | 
						
							| 8 |  | mapdhc.o |  |-  .0. = ( 0g ` U ) | 
						
							| 9 |  | mapdh.n |  |-  N = ( LSpan ` U ) | 
						
							| 10 |  | mapdh.c |  |-  C = ( ( LCDual ` K ) ` W ) | 
						
							| 11 |  | mapdh.d |  |-  D = ( Base ` C ) | 
						
							| 12 |  | mapdh.r |  |-  R = ( -g ` C ) | 
						
							| 13 |  | mapdh.j |  |-  J = ( LSpan ` C ) | 
						
							| 14 |  | mapdh.k |  |-  ( ph -> ( K e. HL /\ W e. H ) ) | 
						
							| 15 |  | mapdhc.f |  |-  ( ph -> F e. D ) | 
						
							| 16 |  | mapdh.mn |  |-  ( ph -> ( M ` ( N ` { X } ) ) = ( J ` { F } ) ) | 
						
							| 17 |  | mapdhcl.x |  |-  ( ph -> X e. ( V \ { .0. } ) ) | 
						
							| 18 |  | mapdh.p |  |-  .+ = ( +g ` U ) | 
						
							| 19 |  | mapdh.a |  |-  .+b = ( +g ` C ) | 
						
							| 20 |  | mapdh6i.xn |  |-  ( ph -> -. X e. ( N ` { Y , Z } ) ) | 
						
							| 21 |  | mapdh6i.y |  |-  ( ph -> Y e. ( V \ { .0. } ) ) | 
						
							| 22 |  | mapdh6i.z |  |-  ( ph -> Z e. ( V \ { .0. } ) ) | 
						
							| 23 |  | mapdh6i.yz |  |-  ( ph -> ( N ` { Y } ) = ( N ` { Z } ) ) | 
						
							| 24 | 17 | eldifad |  |-  ( ph -> X e. V ) | 
						
							| 25 | 21 | eldifad |  |-  ( ph -> Y e. V ) | 
						
							| 26 | 3 5 6 9 14 24 25 | dvh3dim |  |-  ( ph -> E. w e. V -. w e. ( N ` { X , Y } ) ) | 
						
							| 27 | 14 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> ( K e. HL /\ W e. H ) ) | 
						
							| 28 | 15 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> F e. D ) | 
						
							| 29 | 16 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> ( M ` ( N ` { X } ) ) = ( J ` { F } ) ) | 
						
							| 30 | 17 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> X e. ( V \ { .0. } ) ) | 
						
							| 31 | 20 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> -. X e. ( N ` { Y , Z } ) ) | 
						
							| 32 | 23 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> ( N ` { Y } ) = ( N ` { Z } ) ) | 
						
							| 33 | 21 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> Y e. ( V \ { .0. } ) ) | 
						
							| 34 | 22 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> Z e. ( V \ { .0. } ) ) | 
						
							| 35 |  | eqid |  |-  ( LSubSp ` U ) = ( LSubSp ` U ) | 
						
							| 36 | 3 5 14 | dvhlmod |  |-  ( ph -> U e. LMod ) | 
						
							| 37 | 36 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> U e. LMod ) | 
						
							| 38 | 6 35 9 36 24 25 | lspprcl |  |-  ( ph -> ( N ` { X , Y } ) e. ( LSubSp ` U ) ) | 
						
							| 39 | 38 | 3ad2ant1 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> ( N ` { X , Y } ) e. ( LSubSp ` U ) ) | 
						
							| 40 |  | simp2 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> w e. V ) | 
						
							| 41 |  | simp3 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> -. w e. ( N ` { X , Y } ) ) | 
						
							| 42 | 8 35 37 39 40 41 | lssneln0 |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> w e. ( V \ { .0. } ) ) | 
						
							| 43 | 1 2 3 4 5 6 7 8 9 10 11 12 13 27 28 29 30 18 19 31 32 33 34 42 41 | mapdh6hN |  |-  ( ( ph /\ w e. V /\ -. w e. ( N ` { X , Y } ) ) -> ( I ` <. X , F , ( Y .+ Z ) >. ) = ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) | 
						
							| 44 | 43 | rexlimdv3a |  |-  ( ph -> ( E. w e. V -. w e. ( N ` { X , Y } ) -> ( I ` <. X , F , ( Y .+ Z ) >. ) = ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) ) | 
						
							| 45 | 26 44 | mpd |  |-  ( ph -> ( I ` <. X , F , ( Y .+ Z ) >. ) = ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) |