| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lspindp1.v |  |-  V = ( Base ` W ) | 
						
							| 2 |  | lspindp1.o |  |-  .0. = ( 0g ` W ) | 
						
							| 3 |  | lspindp1.n |  |-  N = ( LSpan ` W ) | 
						
							| 4 |  | lspindp1.w |  |-  ( ph -> W e. LVec ) | 
						
							| 5 |  | lspindp1.y |  |-  ( ph -> X e. ( V \ { .0. } ) ) | 
						
							| 6 |  | lspindp1.z |  |-  ( ph -> Y e. V ) | 
						
							| 7 |  | lspindp1.x |  |-  ( ph -> Z e. V ) | 
						
							| 8 |  | lspindp1.q |  |-  ( ph -> ( N ` { X } ) =/= ( N ` { Y } ) ) | 
						
							| 9 |  | lspindp1.e |  |-  ( ph -> -. Z e. ( N ` { X , Y } ) ) | 
						
							| 10 | 1 2 3 4 5 6 7 8 9 | lspindp1 |  |-  ( ph -> ( ( N ` { Z } ) =/= ( N ` { Y } ) /\ -. X e. ( N ` { Z , Y } ) ) ) | 
						
							| 11 | 10 | simpld |  |-  ( ph -> ( N ` { Z } ) =/= ( N ` { Y } ) ) | 
						
							| 12 | 11 | necomd |  |-  ( ph -> ( N ` { Y } ) =/= ( N ` { Z } ) ) | 
						
							| 13 | 10 | simprd |  |-  ( ph -> -. X e. ( N ` { Z , Y } ) ) | 
						
							| 14 |  | prcom |  |-  { Z , Y } = { Y , Z } | 
						
							| 15 | 14 | fveq2i |  |-  ( N ` { Z , Y } ) = ( N ` { Y , Z } ) | 
						
							| 16 | 15 | eleq2i |  |-  ( X e. ( N ` { Z , Y } ) <-> X e. ( N ` { Y , Z } ) ) | 
						
							| 17 | 13 16 | sylnib |  |-  ( ph -> -. X e. ( N ` { Y , Z } ) ) | 
						
							| 18 | 12 17 | jca |  |-  ( ph -> ( ( N ` { Y } ) =/= ( N ` { Z } ) /\ -. X e. ( N ` { Y , Z } ) ) ) |