| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdindp1.v |  |-  V = ( Base ` W ) | 
						
							| 2 |  | mapdindp1.p |  |-  .+ = ( +g ` W ) | 
						
							| 3 |  | mapdindp1.o |  |-  .0. = ( 0g ` W ) | 
						
							| 4 |  | mapdindp1.n |  |-  N = ( LSpan ` W ) | 
						
							| 5 |  | mapdindp1.w |  |-  ( ph -> W e. LVec ) | 
						
							| 6 |  | mapdindp1.x |  |-  ( ph -> X e. ( V \ { .0. } ) ) | 
						
							| 7 |  | mapdindp1.y |  |-  ( ph -> Y e. ( V \ { .0. } ) ) | 
						
							| 8 |  | mapdindp1.z |  |-  ( ph -> Z e. ( V \ { .0. } ) ) | 
						
							| 9 |  | mapdindp1.W |  |-  ( ph -> w e. ( V \ { .0. } ) ) | 
						
							| 10 |  | mapdindp1.e |  |-  ( ph -> ( N ` { Y } ) = ( N ` { Z } ) ) | 
						
							| 11 |  | mapdindp1.ne |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Y } ) ) | 
						
							| 12 |  | mapdindp1.f |  |-  ( ph -> -. w e. ( N ` { X , Y } ) ) | 
						
							| 13 |  | eldifsni |  |-  ( X e. ( V \ { .0. } ) -> X =/= .0. ) | 
						
							| 14 | 6 13 | syl |  |-  ( ph -> X =/= .0. ) | 
						
							| 15 |  | lveclmod |  |-  ( W e. LVec -> W e. LMod ) | 
						
							| 16 | 5 15 | syl |  |-  ( ph -> W e. LMod ) | 
						
							| 17 | 3 4 | lspsn0 |  |-  ( W e. LMod -> ( N ` { .0. } ) = { .0. } ) | 
						
							| 18 | 16 17 | syl |  |-  ( ph -> ( N ` { .0. } ) = { .0. } ) | 
						
							| 19 | 18 | eqeq2d |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { .0. } ) <-> ( N ` { X } ) = { .0. } ) ) | 
						
							| 20 | 6 | eldifad |  |-  ( ph -> X e. V ) | 
						
							| 21 | 1 3 4 | lspsneq0 |  |-  ( ( W e. LMod /\ X e. V ) -> ( ( N ` { X } ) = { .0. } <-> X = .0. ) ) | 
						
							| 22 | 16 20 21 | syl2anc |  |-  ( ph -> ( ( N ` { X } ) = { .0. } <-> X = .0. ) ) | 
						
							| 23 | 19 22 | bitrd |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { .0. } ) <-> X = .0. ) ) | 
						
							| 24 | 23 | necon3bid |  |-  ( ph -> ( ( N ` { X } ) =/= ( N ` { .0. } ) <-> X =/= .0. ) ) | 
						
							| 25 | 14 24 | mpbird |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { .0. } ) ) | 
						
							| 26 | 25 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) = .0. ) -> ( N ` { X } ) =/= ( N ` { .0. } ) ) | 
						
							| 27 |  | sneq |  |-  ( ( Y .+ Z ) = .0. -> { ( Y .+ Z ) } = { .0. } ) | 
						
							| 28 | 27 | fveq2d |  |-  ( ( Y .+ Z ) = .0. -> ( N ` { ( Y .+ Z ) } ) = ( N ` { .0. } ) ) | 
						
							| 29 | 28 | adantl |  |-  ( ( ph /\ ( Y .+ Z ) = .0. ) -> ( N ` { ( Y .+ Z ) } ) = ( N ` { .0. } ) ) | 
						
							| 30 | 26 29 | neeqtrrd |  |-  ( ( ph /\ ( Y .+ Z ) = .0. ) -> ( N ` { X } ) =/= ( N ` { ( Y .+ Z ) } ) ) | 
						
							| 31 | 11 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> ( N ` { X } ) =/= ( N ` { Y } ) ) | 
						
							| 32 | 5 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> W e. LVec ) | 
						
							| 33 | 6 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> X e. ( V \ { .0. } ) ) | 
						
							| 34 | 7 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> Y e. ( V \ { .0. } ) ) | 
						
							| 35 | 8 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> Z e. ( V \ { .0. } ) ) | 
						
							| 36 | 9 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> w e. ( V \ { .0. } ) ) | 
						
							| 37 | 10 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> ( N ` { Y } ) = ( N ` { Z } ) ) | 
						
							| 38 | 12 | adantr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> -. w e. ( N ` { X , Y } ) ) | 
						
							| 39 |  | simpr |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> ( Y .+ Z ) =/= .0. ) | 
						
							| 40 | 1 2 3 4 32 33 34 35 36 37 31 38 39 | mapdindp0 |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> ( N ` { ( Y .+ Z ) } ) = ( N ` { Y } ) ) | 
						
							| 41 | 31 40 | neeqtrrd |  |-  ( ( ph /\ ( Y .+ Z ) =/= .0. ) -> ( N ` { X } ) =/= ( N ` { ( Y .+ Z ) } ) ) | 
						
							| 42 | 30 41 | pm2.61dane |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { ( Y .+ Z ) } ) ) |