| 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 |  | mapdhe6.y |  |-  ( ph -> Y e. ( V \ { .0. } ) ) | 
						
							| 21 |  | mapdhe6.z |  |-  ( ph -> Z e. ( V \ { .0. } ) ) | 
						
							| 22 |  | mapdhe6.xn |  |-  ( ph -> -. X e. ( N ` { Y , Z } ) ) | 
						
							| 23 |  | mapdh6.yz |  |-  ( ph -> ( N ` { Y } ) =/= ( N ` { Z } ) ) | 
						
							| 24 |  | mapdh6.fg |  |-  ( ph -> ( I ` <. X , F , Y >. ) = G ) | 
						
							| 25 |  | mapdh6.fe |  |-  ( ph -> ( I ` <. X , F , Z >. ) = E ) | 
						
							| 26 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | mapdh6lem2N |  |-  ( ph -> ( M ` ( N ` { ( Y .+ Z ) } ) ) = ( J ` { ( G .+b E ) } ) ) | 
						
							| 27 | 24 25 | oveq12d |  |-  ( ph -> ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) = ( G .+b E ) ) | 
						
							| 28 | 27 | sneqd |  |-  ( ph -> { ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) } = { ( G .+b E ) } ) | 
						
							| 29 | 28 | fveq2d |  |-  ( ph -> ( J ` { ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) } ) = ( J ` { ( G .+b E ) } ) ) | 
						
							| 30 | 26 29 | eqtr4d |  |-  ( ph -> ( M ` ( N ` { ( Y .+ Z ) } ) ) = ( J ` { ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) } ) ) | 
						
							| 31 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | mapdh6lem1N |  |-  ( ph -> ( M ` ( N ` { ( X .- ( Y .+ Z ) ) } ) ) = ( J ` { ( F R ( G .+b E ) ) } ) ) | 
						
							| 32 | 27 | oveq2d |  |-  ( ph -> ( F R ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) = ( F R ( G .+b E ) ) ) | 
						
							| 33 | 32 | sneqd |  |-  ( ph -> { ( F R ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) } = { ( F R ( G .+b E ) ) } ) | 
						
							| 34 | 33 | fveq2d |  |-  ( ph -> ( J ` { ( F R ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) } ) = ( J ` { ( F R ( G .+b E ) ) } ) ) | 
						
							| 35 | 31 34 | eqtr4d |  |-  ( ph -> ( M ` ( N ` { ( X .- ( Y .+ Z ) ) } ) ) = ( J ` { ( F R ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) } ) ) | 
						
							| 36 | 3 5 14 | dvhlmod |  |-  ( ph -> U e. LMod ) | 
						
							| 37 | 20 | eldifad |  |-  ( ph -> Y e. V ) | 
						
							| 38 | 21 | eldifad |  |-  ( ph -> Z e. V ) | 
						
							| 39 | 6 18 | lmodvacl |  |-  ( ( U e. LMod /\ Y e. V /\ Z e. V ) -> ( Y .+ Z ) e. V ) | 
						
							| 40 | 36 37 38 39 | syl3anc |  |-  ( ph -> ( Y .+ Z ) e. V ) | 
						
							| 41 | 6 18 8 9 36 37 38 23 | lmodindp1 |  |-  ( ph -> ( Y .+ Z ) =/= .0. ) | 
						
							| 42 |  | eldifsn |  |-  ( ( Y .+ Z ) e. ( V \ { .0. } ) <-> ( ( Y .+ Z ) e. V /\ ( Y .+ Z ) =/= .0. ) ) | 
						
							| 43 | 40 41 42 | sylanbrc |  |-  ( ph -> ( Y .+ Z ) e. ( V \ { .0. } ) ) | 
						
							| 44 | 3 10 14 | lcdlmod |  |-  ( ph -> C e. LMod ) | 
						
							| 45 | 3 5 14 | dvhlvec |  |-  ( ph -> U e. LVec ) | 
						
							| 46 | 17 | eldifad |  |-  ( ph -> X e. V ) | 
						
							| 47 | 6 8 9 45 37 21 46 23 22 | lspindp2 |  |-  ( ph -> ( ( N ` { X } ) =/= ( N ` { Y } ) /\ -. Z e. ( N ` { X , Y } ) ) ) | 
						
							| 48 | 47 | simpld |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Y } ) ) | 
						
							| 49 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 37 48 | mapdhcl |  |-  ( ph -> ( I ` <. X , F , Y >. ) e. D ) | 
						
							| 50 | 6 8 9 45 20 38 46 23 22 | lspindp1 |  |-  ( ph -> ( ( N ` { X } ) =/= ( N ` { Z } ) /\ -. Y e. ( N ` { X , Z } ) ) ) | 
						
							| 51 | 50 | simpld |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Z } ) ) | 
						
							| 52 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 38 51 | mapdhcl |  |-  ( ph -> ( I ` <. X , F , Z >. ) e. D ) | 
						
							| 53 | 11 19 | lmodvacl |  |-  ( ( C e. LMod /\ ( I ` <. X , F , Y >. ) e. D /\ ( I ` <. X , F , Z >. ) e. D ) -> ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) e. D ) | 
						
							| 54 | 44 49 52 53 | syl3anc |  |-  ( ph -> ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) e. D ) | 
						
							| 55 |  | eqid |  |-  ( LSubSp ` U ) = ( LSubSp ` U ) | 
						
							| 56 | 6 55 9 36 37 38 | lspprcl |  |-  ( ph -> ( N ` { Y , Z } ) e. ( LSubSp ` U ) ) | 
						
							| 57 | 6 18 9 36 37 38 | lspprvacl |  |-  ( ph -> ( Y .+ Z ) e. ( N ` { Y , Z } ) ) | 
						
							| 58 | 55 9 36 56 57 | ellspsn5 |  |-  ( ph -> ( N ` { ( Y .+ Z ) } ) C_ ( N ` { Y , Z } ) ) | 
						
							| 59 | 6 55 9 36 56 46 | ellspsn5b |  |-  ( ph -> ( X e. ( N ` { Y , Z } ) <-> ( N ` { X } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 60 | 22 59 | mtbid |  |-  ( ph -> -. ( N ` { X } ) C_ ( N ` { Y , Z } ) ) | 
						
							| 61 |  | nssne2 |  |-  ( ( ( N ` { ( Y .+ Z ) } ) C_ ( N ` { Y , Z } ) /\ -. ( N ` { X } ) C_ ( N ` { Y , Z } ) ) -> ( N ` { ( Y .+ Z ) } ) =/= ( N ` { X } ) ) | 
						
							| 62 | 58 60 61 | syl2anc |  |-  ( ph -> ( N ` { ( Y .+ Z ) } ) =/= ( N ` { X } ) ) | 
						
							| 63 | 62 | necomd |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { ( Y .+ Z ) } ) ) | 
						
							| 64 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 43 54 63 | mapdheq |  |-  ( ph -> ( ( I ` <. X , F , ( Y .+ Z ) >. ) = ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) <-> ( ( M ` ( N ` { ( Y .+ Z ) } ) ) = ( J ` { ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) } ) /\ ( M ` ( N ` { ( X .- ( Y .+ Z ) ) } ) ) = ( J ` { ( F R ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) } ) ) ) ) | 
						
							| 65 | 30 35 64 | mpbir2and |  |-  ( ph -> ( I ` <. X , F , ( Y .+ Z ) >. ) = ( ( I ` <. X , F , Y >. ) .+b ( I ` <. X , F , Z >. ) ) ) |