| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cssmre.v |  |-  V = ( Base ` W ) | 
						
							| 2 |  | cssmre.c |  |-  C = ( ClSubSp ` W ) | 
						
							| 3 | 1 2 | cssss |  |-  ( x e. C -> x C_ V ) | 
						
							| 4 |  | velpw |  |-  ( x e. ~P V <-> x C_ V ) | 
						
							| 5 | 3 4 | sylibr |  |-  ( x e. C -> x e. ~P V ) | 
						
							| 6 | 5 | a1i |  |-  ( W e. PreHil -> ( x e. C -> x e. ~P V ) ) | 
						
							| 7 | 6 | ssrdv |  |-  ( W e. PreHil -> C C_ ~P V ) | 
						
							| 8 | 1 2 | css1 |  |-  ( W e. PreHil -> V e. C ) | 
						
							| 9 |  | intss1 |  |-  ( z e. x -> |^| x C_ z ) | 
						
							| 10 |  | eqid |  |-  ( ocv ` W ) = ( ocv ` W ) | 
						
							| 11 | 10 | ocv2ss |  |-  ( |^| x C_ z -> ( ( ocv ` W ) ` z ) C_ ( ( ocv ` W ) ` |^| x ) ) | 
						
							| 12 | 10 | ocv2ss |  |-  ( ( ( ocv ` W ) ` z ) C_ ( ( ocv ` W ) ` |^| x ) -> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 13 | 9 11 12 | 3syl |  |-  ( z e. x -> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 14 | 13 | ad2antll |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 15 |  | simprl |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) ) | 
						
							| 16 | 14 15 | sseldd |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 17 |  | simpl2 |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> x C_ C ) | 
						
							| 18 |  | simprr |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> z e. x ) | 
						
							| 19 | 17 18 | sseldd |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> z e. C ) | 
						
							| 20 | 10 2 | cssi |  |-  ( z e. C -> z = ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 21 | 19 20 | syl |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> z = ( ( ocv ` W ) ` ( ( ocv ` W ) ` z ) ) ) | 
						
							| 22 | 16 21 | eleqtrrd |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) /\ z e. x ) ) -> y e. z ) | 
						
							| 23 | 22 | expr |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) ) -> ( z e. x -> y e. z ) ) | 
						
							| 24 | 23 | alrimiv |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) ) -> A. z ( z e. x -> y e. z ) ) | 
						
							| 25 |  | vex |  |-  y e. _V | 
						
							| 26 | 25 | elint |  |-  ( y e. |^| x <-> A. z ( z e. x -> y e. z ) ) | 
						
							| 27 | 24 26 | sylibr |  |-  ( ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) /\ y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) ) -> y e. |^| x ) | 
						
							| 28 | 27 | ex |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> ( y e. ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) -> y e. |^| x ) ) | 
						
							| 29 | 28 | ssrdv |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ |^| x ) | 
						
							| 30 |  | simp1 |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> W e. PreHil ) | 
						
							| 31 |  | intssuni |  |-  ( x =/= (/) -> |^| x C_ U. x ) | 
						
							| 32 | 31 | 3ad2ant3 |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> |^| x C_ U. x ) | 
						
							| 33 |  | simp2 |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> x C_ C ) | 
						
							| 34 | 7 | 3ad2ant1 |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> C C_ ~P V ) | 
						
							| 35 | 33 34 | sstrd |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> x C_ ~P V ) | 
						
							| 36 |  | sspwuni |  |-  ( x C_ ~P V <-> U. x C_ V ) | 
						
							| 37 | 35 36 | sylib |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> U. x C_ V ) | 
						
							| 38 | 32 37 | sstrd |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> |^| x C_ V ) | 
						
							| 39 | 1 2 10 | iscss2 |  |-  ( ( W e. PreHil /\ |^| x C_ V ) -> ( |^| x e. C <-> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ |^| x ) ) | 
						
							| 40 | 30 38 39 | syl2anc |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> ( |^| x e. C <-> ( ( ocv ` W ) ` ( ( ocv ` W ) ` |^| x ) ) C_ |^| x ) ) | 
						
							| 41 | 29 40 | mpbird |  |-  ( ( W e. PreHil /\ x C_ C /\ x =/= (/) ) -> |^| x e. C ) | 
						
							| 42 | 7 8 41 | ismred |  |-  ( W e. PreHil -> C e. ( Moore ` V ) ) |