| Step | Hyp | Ref | Expression | 
						
							| 1 |  | neibastop1.1 |  |-  ( ph -> X e. V ) | 
						
							| 2 |  | neibastop1.2 |  |-  ( ph -> F : X --> ( ~P ~P X \ { (/) } ) ) | 
						
							| 3 |  | neibastop1.3 |  |-  ( ( ph /\ ( x e. X /\ v e. ( F ` x ) /\ w e. ( F ` x ) ) ) -> ( ( F ` x ) i^i ~P ( v i^i w ) ) =/= (/) ) | 
						
							| 4 |  | neibastop1.4 |  |-  J = { o e. ~P X | A. x e. o ( ( F ` x ) i^i ~P o ) =/= (/) } | 
						
							| 5 |  | neibastop1.5 |  |-  ( ( ph /\ ( x e. X /\ v e. ( F ` x ) ) ) -> x e. v ) | 
						
							| 6 |  | neibastop1.6 |  |-  ( ( ph /\ ( x e. X /\ v e. ( F ` x ) ) ) -> E. t e. ( F ` x ) A. y e. t ( ( F ` y ) i^i ~P v ) =/= (/) ) | 
						
							| 7 | 1 2 3 4 | neibastop1 |  |-  ( ph -> J e. ( TopOn ` X ) ) | 
						
							| 8 | 1 2 3 4 5 6 | neibastop2 |  |-  ( ( ph /\ z e. X ) -> ( n e. ( ( nei ` J ) ` { z } ) <-> ( n C_ X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) ) ) | 
						
							| 9 |  | velpw |  |-  ( n e. ~P X <-> n C_ X ) | 
						
							| 10 | 9 | anbi1i |  |-  ( ( n e. ~P X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) <-> ( n C_ X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) ) | 
						
							| 11 | 8 10 | bitr4di |  |-  ( ( ph /\ z e. X ) -> ( n e. ( ( nei ` J ) ` { z } ) <-> ( n e. ~P X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) ) ) | 
						
							| 12 | 11 | eqabdv |  |-  ( ( ph /\ z e. X ) -> ( ( nei ` J ) ` { z } ) = { n | ( n e. ~P X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) } ) | 
						
							| 13 |  | df-rab |  |-  { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } = { n | ( n e. ~P X /\ ( ( F ` z ) i^i ~P n ) =/= (/) ) } | 
						
							| 14 | 12 13 | eqtr4di |  |-  ( ( ph /\ z e. X ) -> ( ( nei ` J ) ` { z } ) = { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } ) | 
						
							| 15 | 14 | ralrimiva |  |-  ( ph -> A. z e. X ( ( nei ` J ) ` { z } ) = { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } ) | 
						
							| 16 |  | sneq |  |-  ( x = z -> { x } = { z } ) | 
						
							| 17 | 16 | fveq2d |  |-  ( x = z -> ( ( nei ` J ) ` { x } ) = ( ( nei ` J ) ` { z } ) ) | 
						
							| 18 |  | fveq2 |  |-  ( x = z -> ( F ` x ) = ( F ` z ) ) | 
						
							| 19 | 18 | ineq1d |  |-  ( x = z -> ( ( F ` x ) i^i ~P n ) = ( ( F ` z ) i^i ~P n ) ) | 
						
							| 20 | 19 | neeq1d |  |-  ( x = z -> ( ( ( F ` x ) i^i ~P n ) =/= (/) <-> ( ( F ` z ) i^i ~P n ) =/= (/) ) ) | 
						
							| 21 | 20 | rabbidv |  |-  ( x = z -> { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } = { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } ) | 
						
							| 22 | 17 21 | eqeq12d |  |-  ( x = z -> ( ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> ( ( nei ` J ) ` { z } ) = { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 23 | 22 | cbvralvw |  |-  ( A. x e. X ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> A. z e. X ( ( nei ` J ) ` { z } ) = { n e. ~P X | ( ( F ` z ) i^i ~P n ) =/= (/) } ) | 
						
							| 24 | 15 23 | sylibr |  |-  ( ph -> A. x e. X ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) | 
						
							| 25 |  | toponuni |  |-  ( j e. ( TopOn ` X ) -> X = U. j ) | 
						
							| 26 |  | eqimss2 |  |-  ( X = U. j -> U. j C_ X ) | 
						
							| 27 | 25 26 | syl |  |-  ( j e. ( TopOn ` X ) -> U. j C_ X ) | 
						
							| 28 |  | sspwuni |  |-  ( j C_ ~P X <-> U. j C_ X ) | 
						
							| 29 | 27 28 | sylibr |  |-  ( j e. ( TopOn ` X ) -> j C_ ~P X ) | 
						
							| 30 | 29 | ad2antlr |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> j C_ ~P X ) | 
						
							| 31 |  | sseqin2 |  |-  ( j C_ ~P X <-> ( ~P X i^i j ) = j ) | 
						
							| 32 | 30 31 | sylib |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> ( ~P X i^i j ) = j ) | 
						
							| 33 |  | topontop |  |-  ( j e. ( TopOn ` X ) -> j e. Top ) | 
						
							| 34 | 33 | ad3antlr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ o e. ~P X ) -> j e. Top ) | 
						
							| 35 |  | eltop2 |  |-  ( j e. Top -> ( o e. j <-> A. x e. o E. z e. j ( x e. z /\ z C_ o ) ) ) | 
						
							| 36 | 34 35 | syl |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ o e. ~P X ) -> ( o e. j <-> A. x e. o E. z e. j ( x e. z /\ z C_ o ) ) ) | 
						
							| 37 |  | elpwi |  |-  ( o e. ~P X -> o C_ X ) | 
						
							| 38 |  | ssralv |  |-  ( o C_ X -> ( A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> A. x e. o ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 39 | 37 38 | syl |  |-  ( o e. ~P X -> ( A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> A. x e. o ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 40 | 39 | adantl |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) -> ( A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> A. x e. o ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 41 |  | simprr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) | 
						
							| 42 | 41 | eleq2d |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> ( o e. ( ( nei ` j ) ` { x } ) <-> o e. { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 43 | 33 | ad3antlr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> j e. Top ) | 
						
							| 44 | 25 | adantl |  |-  ( ( ph /\ j e. ( TopOn ` X ) ) -> X = U. j ) | 
						
							| 45 | 44 | sseq2d |  |-  ( ( ph /\ j e. ( TopOn ` X ) ) -> ( o C_ X <-> o C_ U. j ) ) | 
						
							| 46 | 45 | biimpa |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o C_ X ) -> o C_ U. j ) | 
						
							| 47 | 37 46 | sylan2 |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) -> o C_ U. j ) | 
						
							| 48 | 47 | sselda |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ x e. o ) -> x e. U. j ) | 
						
							| 49 | 48 | adantrr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> x e. U. j ) | 
						
							| 50 | 47 | adantr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> o C_ U. j ) | 
						
							| 51 |  | eqid |  |-  U. j = U. j | 
						
							| 52 | 51 | isneip |  |-  ( ( j e. Top /\ x e. U. j ) -> ( o e. ( ( nei ` j ) ` { x } ) <-> ( o C_ U. j /\ E. z e. j ( x e. z /\ z C_ o ) ) ) ) | 
						
							| 53 | 52 | baibd |  |-  ( ( ( j e. Top /\ x e. U. j ) /\ o C_ U. j ) -> ( o e. ( ( nei ` j ) ` { x } ) <-> E. z e. j ( x e. z /\ z C_ o ) ) ) | 
						
							| 54 | 43 49 50 53 | syl21anc |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> ( o e. ( ( nei ` j ) ` { x } ) <-> E. z e. j ( x e. z /\ z C_ o ) ) ) | 
						
							| 55 |  | pweq |  |-  ( n = o -> ~P n = ~P o ) | 
						
							| 56 | 55 | ineq2d |  |-  ( n = o -> ( ( F ` x ) i^i ~P n ) = ( ( F ` x ) i^i ~P o ) ) | 
						
							| 57 | 56 | neeq1d |  |-  ( n = o -> ( ( ( F ` x ) i^i ~P n ) =/= (/) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 58 | 57 | elrab3 |  |-  ( o e. ~P X -> ( o e. { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 59 | 58 | ad2antlr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> ( o e. { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 60 | 42 54 59 | 3bitr3d |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ ( x e. o /\ ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) -> ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 61 | 60 | expr |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ x e. o ) -> ( ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) ) | 
						
							| 62 | 61 | ralimdva |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) -> ( A. x e. o ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> A. x e. o ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) ) | 
						
							| 63 | 40 62 | syld |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) -> ( A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } -> A. x e. o ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) ) | 
						
							| 64 | 63 | imp |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ o e. ~P X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> A. x e. o ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 65 | 64 | an32s |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ o e. ~P X ) -> A. x e. o ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 66 |  | ralbi |  |-  ( A. x e. o ( E. z e. j ( x e. z /\ z C_ o ) <-> ( ( F ` x ) i^i ~P o ) =/= (/) ) -> ( A. x e. o E. z e. j ( x e. z /\ z C_ o ) <-> A. x e. o ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 67 | 65 66 | syl |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ o e. ~P X ) -> ( A. x e. o E. z e. j ( x e. z /\ z C_ o ) <-> A. x e. o ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 68 | 36 67 | bitrd |  |-  ( ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ o e. ~P X ) -> ( o e. j <-> A. x e. o ( ( F ` x ) i^i ~P o ) =/= (/) ) ) | 
						
							| 69 | 68 | rabbi2dva |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> ( ~P X i^i j ) = { o e. ~P X | A. x e. o ( ( F ` x ) i^i ~P o ) =/= (/) } ) | 
						
							| 70 | 69 4 | eqtr4di |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> ( ~P X i^i j ) = J ) | 
						
							| 71 | 32 70 | eqtr3d |  |-  ( ( ( ph /\ j e. ( TopOn ` X ) ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> j = J ) | 
						
							| 72 | 71 | expl |  |-  ( ph -> ( ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> j = J ) ) | 
						
							| 73 | 72 | alrimiv |  |-  ( ph -> A. j ( ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> j = J ) ) | 
						
							| 74 |  | eleq1 |  |-  ( j = J -> ( j e. ( TopOn ` X ) <-> J e. ( TopOn ` X ) ) ) | 
						
							| 75 |  | fveq2 |  |-  ( j = J -> ( nei ` j ) = ( nei ` J ) ) | 
						
							| 76 | 75 | fveq1d |  |-  ( j = J -> ( ( nei ` j ) ` { x } ) = ( ( nei ` J ) ` { x } ) ) | 
						
							| 77 | 76 | eqeq1d |  |-  ( j = J -> ( ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 78 | 77 | ralbidv |  |-  ( j = J -> ( A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> A. x e. X ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 79 | 74 78 | anbi12d |  |-  ( j = J -> ( ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) <-> ( J e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) ) | 
						
							| 80 | 79 | eqeu |  |-  ( ( J e. ( TopOn ` X ) /\ ( J e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` J ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) /\ A. j ( ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) -> j = J ) ) -> E! j ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 81 | 7 7 24 73 80 | syl121anc |  |-  ( ph -> E! j ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 82 |  | df-reu |  |-  ( E! j e. ( TopOn ` X ) A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } <-> E! j ( j e. ( TopOn ` X ) /\ A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) ) | 
						
							| 83 | 81 82 | sylibr |  |-  ( ph -> E! j e. ( TopOn ` X ) A. x e. X ( ( nei ` j ) ` { x } ) = { n e. ~P X | ( ( F ` x ) i^i ~P n ) =/= (/) } ) |