| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lspindpi.v |  |-  V = ( Base ` W ) | 
						
							| 2 |  | lspindpi.n |  |-  N = ( LSpan ` W ) | 
						
							| 3 |  | lspindpi.w |  |-  ( ph -> W e. LVec ) | 
						
							| 4 |  | lspindpi.x |  |-  ( ph -> X e. V ) | 
						
							| 5 |  | lspindpi.y |  |-  ( ph -> Y e. V ) | 
						
							| 6 |  | lspindpi.z |  |-  ( ph -> Z e. V ) | 
						
							| 7 |  | lspindpi.e |  |-  ( ph -> -. X e. ( N ` { Y , Z } ) ) | 
						
							| 8 |  | lveclmod |  |-  ( W e. LVec -> W e. LMod ) | 
						
							| 9 | 3 8 | syl |  |-  ( ph -> W e. LMod ) | 
						
							| 10 |  | eqid |  |-  ( LSubSp ` W ) = ( LSubSp ` W ) | 
						
							| 11 | 10 | lsssssubg |  |-  ( W e. LMod -> ( LSubSp ` W ) C_ ( SubGrp ` W ) ) | 
						
							| 12 | 9 11 | syl |  |-  ( ph -> ( LSubSp ` W ) C_ ( SubGrp ` W ) ) | 
						
							| 13 | 1 10 2 | lspsncl |  |-  ( ( W e. LMod /\ Y e. V ) -> ( N ` { Y } ) e. ( LSubSp ` W ) ) | 
						
							| 14 | 9 5 13 | syl2anc |  |-  ( ph -> ( N ` { Y } ) e. ( LSubSp ` W ) ) | 
						
							| 15 | 12 14 | sseldd |  |-  ( ph -> ( N ` { Y } ) e. ( SubGrp ` W ) ) | 
						
							| 16 | 1 10 2 | lspsncl |  |-  ( ( W e. LMod /\ Z e. V ) -> ( N ` { Z } ) e. ( LSubSp ` W ) ) | 
						
							| 17 | 9 6 16 | syl2anc |  |-  ( ph -> ( N ` { Z } ) e. ( LSubSp ` W ) ) | 
						
							| 18 | 12 17 | sseldd |  |-  ( ph -> ( N ` { Z } ) e. ( SubGrp ` W ) ) | 
						
							| 19 |  | eqid |  |-  ( LSSum ` W ) = ( LSSum ` W ) | 
						
							| 20 | 19 | lsmub1 |  |-  ( ( ( N ` { Y } ) e. ( SubGrp ` W ) /\ ( N ` { Z } ) e. ( SubGrp ` W ) ) -> ( N ` { Y } ) C_ ( ( N ` { Y } ) ( LSSum ` W ) ( N ` { Z } ) ) ) | 
						
							| 21 | 15 18 20 | syl2anc |  |-  ( ph -> ( N ` { Y } ) C_ ( ( N ` { Y } ) ( LSSum ` W ) ( N ` { Z } ) ) ) | 
						
							| 22 | 1 2 19 9 5 6 | lsmpr |  |-  ( ph -> ( N ` { Y , Z } ) = ( ( N ` { Y } ) ( LSSum ` W ) ( N ` { Z } ) ) ) | 
						
							| 23 | 21 22 | sseqtrrd |  |-  ( ph -> ( N ` { Y } ) C_ ( N ` { Y , Z } ) ) | 
						
							| 24 |  | sseq1 |  |-  ( ( N ` { X } ) = ( N ` { Y } ) -> ( ( N ` { X } ) C_ ( N ` { Y , Z } ) <-> ( N ` { Y } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 25 | 23 24 | syl5ibrcom |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { Y } ) -> ( N ` { X } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 26 | 1 10 2 9 5 6 | lspprcl |  |-  ( ph -> ( N ` { Y , Z } ) e. ( LSubSp ` W ) ) | 
						
							| 27 | 1 10 2 9 26 4 | ellspsn5b |  |-  ( ph -> ( X e. ( N ` { Y , Z } ) <-> ( N ` { X } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 28 | 25 27 | sylibrd |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { Y } ) -> X e. ( N ` { Y , Z } ) ) ) | 
						
							| 29 | 28 | necon3bd |  |-  ( ph -> ( -. X e. ( N ` { Y , Z } ) -> ( N ` { X } ) =/= ( N ` { Y } ) ) ) | 
						
							| 30 | 7 29 | mpd |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Y } ) ) | 
						
							| 31 | 19 | lsmub2 |  |-  ( ( ( N ` { Y } ) e. ( SubGrp ` W ) /\ ( N ` { Z } ) e. ( SubGrp ` W ) ) -> ( N ` { Z } ) C_ ( ( N ` { Y } ) ( LSSum ` W ) ( N ` { Z } ) ) ) | 
						
							| 32 | 15 18 31 | syl2anc |  |-  ( ph -> ( N ` { Z } ) C_ ( ( N ` { Y } ) ( LSSum ` W ) ( N ` { Z } ) ) ) | 
						
							| 33 | 32 22 | sseqtrrd |  |-  ( ph -> ( N ` { Z } ) C_ ( N ` { Y , Z } ) ) | 
						
							| 34 |  | sseq1 |  |-  ( ( N ` { X } ) = ( N ` { Z } ) -> ( ( N ` { X } ) C_ ( N ` { Y , Z } ) <-> ( N ` { Z } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 35 | 33 34 | syl5ibrcom |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { Z } ) -> ( N ` { X } ) C_ ( N ` { Y , Z } ) ) ) | 
						
							| 36 | 35 27 | sylibrd |  |-  ( ph -> ( ( N ` { X } ) = ( N ` { Z } ) -> X e. ( N ` { Y , Z } ) ) ) | 
						
							| 37 | 36 | necon3bd |  |-  ( ph -> ( -. X e. ( N ` { Y , Z } ) -> ( N ` { X } ) =/= ( N ` { Z } ) ) ) | 
						
							| 38 | 7 37 | mpd |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Z } ) ) | 
						
							| 39 | 30 38 | jca |  |-  ( ph -> ( ( N ` { X } ) =/= ( N ` { Y } ) /\ ( N ` { X } ) =/= ( N ` { Z } ) ) ) |