| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							pospo.b | 
							 |-  B = ( Base ` K )  | 
						
						
							| 2 | 
							
								
							 | 
							pospo.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							pospo.s | 
							 |-  .< = ( lt ` K )  | 
						
						
							| 4 | 
							
								3
							 | 
							pltirr | 
							 |-  ( ( K e. Poset /\ x e. B ) -> -. x .< x )  | 
						
						
							| 5 | 
							
								1 3
							 | 
							plttr | 
							 |-  ( ( K e. Poset /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .< y /\ y .< z ) -> x .< z ) )  | 
						
						
							| 6 | 
							
								4 5
							 | 
							ispod | 
							 |-  ( K e. Poset -> .< Po B )  | 
						
						
							| 7 | 
							
								
							 | 
							relres | 
							 |-  Rel ( _I |` B )  | 
						
						
							| 8 | 
							
								7
							 | 
							a1i | 
							 |-  ( K e. Poset -> Rel ( _I |` B ) )  | 
						
						
							| 9 | 
							
								
							 | 
							opabresid | 
							 |-  ( _I |` B ) = { <. x , y >. | ( x e. B /\ y = x ) } | 
						
						
							| 10 | 
							
								9
							 | 
							eqcomi | 
							 |-  { <. x , y >. | ( x e. B /\ y = x ) } = ( _I |` B ) | 
						
						
							| 11 | 
							
								10
							 | 
							eleq2i | 
							 |-  ( <. x , y >. e. { <. x , y >. | ( x e. B /\ y = x ) } <-> <. x , y >. e. ( _I |` B ) ) | 
						
						
							| 12 | 
							
								
							 | 
							opabidw | 
							 |-  ( <. x , y >. e. { <. x , y >. | ( x e. B /\ y = x ) } <-> ( x e. B /\ y = x ) ) | 
						
						
							| 13 | 
							
								11 12
							 | 
							bitr3i | 
							 |-  ( <. x , y >. e. ( _I |` B ) <-> ( x e. B /\ y = x ) )  | 
						
						
							| 14 | 
							
								1 2
							 | 
							posref | 
							 |-  ( ( K e. Poset /\ x e. B ) -> x .<_ x )  | 
						
						
							| 15 | 
							
								
							 | 
							df-br | 
							 |-  ( x .<_ y <-> <. x , y >. e. .<_ )  | 
						
						
							| 16 | 
							
								
							 | 
							breq2 | 
							 |-  ( y = x -> ( x .<_ y <-> x .<_ x ) )  | 
						
						
							| 17 | 
							
								15 16
							 | 
							bitr3id | 
							 |-  ( y = x -> ( <. x , y >. e. .<_ <-> x .<_ x ) )  | 
						
						
							| 18 | 
							
								14 17
							 | 
							syl5ibrcom | 
							 |-  ( ( K e. Poset /\ x e. B ) -> ( y = x -> <. x , y >. e. .<_ ) )  | 
						
						
							| 19 | 
							
								18
							 | 
							expimpd | 
							 |-  ( K e. Poset -> ( ( x e. B /\ y = x ) -> <. x , y >. e. .<_ ) )  | 
						
						
							| 20 | 
							
								13 19
							 | 
							biimtrid | 
							 |-  ( K e. Poset -> ( <. x , y >. e. ( _I |` B ) -> <. x , y >. e. .<_ ) )  | 
						
						
							| 21 | 
							
								8 20
							 | 
							relssdv | 
							 |-  ( K e. Poset -> ( _I |` B ) C_ .<_ )  | 
						
						
							| 22 | 
							
								6 21
							 | 
							jca | 
							 |-  ( K e. Poset -> ( .< Po B /\ ( _I |` B ) C_ .<_ ) )  | 
						
						
							| 23 | 
							
								
							 | 
							simpl | 
							 |-  ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) -> K e. V )  | 
						
						
							| 24 | 
							
								1
							 | 
							a1i | 
							 |-  ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) -> B = ( Base ` K ) )  | 
						
						
							| 25 | 
							
								2
							 | 
							a1i | 
							 |-  ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) -> .<_ = ( le ` K ) )  | 
						
						
							| 26 | 
							
								
							 | 
							equid | 
							 |-  x = x  | 
						
						
							| 27 | 
							
								
							 | 
							simpr | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> x e. B )  | 
						
						
							| 28 | 
							
								
							 | 
							resieq | 
							 |-  ( ( x e. B /\ x e. B ) -> ( x ( _I |` B ) x <-> x = x ) )  | 
						
						
							| 29 | 
							
								27 27 28
							 | 
							syl2anc | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> ( x ( _I |` B ) x <-> x = x ) )  | 
						
						
							| 30 | 
							
								26 29
							 | 
							mpbiri | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> x ( _I |` B ) x )  | 
						
						
							| 31 | 
							
								
							 | 
							simplrr | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> ( _I |` B ) C_ .<_ )  | 
						
						
							| 32 | 
							
								31
							 | 
							ssbrd | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> ( x ( _I |` B ) x -> x .<_ x ) )  | 
						
						
							| 33 | 
							
								30 32
							 | 
							mpd | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B ) -> x .<_ x )  | 
						
						
							| 34 | 
							
								1 2 3
							 | 
							pleval2i | 
							 |-  ( ( x e. B /\ y e. B ) -> ( x .<_ y -> ( x .< y \/ x = y ) ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							3adant1 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( x .<_ y -> ( x .< y \/ x = y ) ) )  | 
						
						
							| 36 | 
							
								1 2 3
							 | 
							pleval2i | 
							 |-  ( ( y e. B /\ x e. B ) -> ( y .<_ x -> ( y .< x \/ y = x ) ) )  | 
						
						
							| 37 | 
							
								36
							 | 
							ancoms | 
							 |-  ( ( x e. B /\ y e. B ) -> ( y .<_ x -> ( y .< x \/ y = x ) ) )  | 
						
						
							| 38 | 
							
								37
							 | 
							3adant1 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( y .<_ x -> ( y .< x \/ y = x ) ) )  | 
						
						
							| 39 | 
							
								
							 | 
							simprl | 
							 |-  ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) -> .< Po B )  | 
						
						
							| 40 | 
							
								
							 | 
							po2nr | 
							 |-  ( ( .< Po B /\ ( x e. B /\ y e. B ) ) -> -. ( x .< y /\ y .< x ) )  | 
						
						
							| 41 | 
							
								40
							 | 
							3impb | 
							 |-  ( ( .< Po B /\ x e. B /\ y e. B ) -> -. ( x .< y /\ y .< x ) )  | 
						
						
							| 42 | 
							
								39 41
							 | 
							syl3an1 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> -. ( x .< y /\ y .< x ) )  | 
						
						
							| 43 | 
							
								42
							 | 
							pm2.21d | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( x .< y /\ y .< x ) -> x = y ) )  | 
						
						
							| 44 | 
							
								
							 | 
							simpl | 
							 |-  ( ( x = y /\ y .< x ) -> x = y )  | 
						
						
							| 45 | 
							
								44
							 | 
							a1i | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( x = y /\ y .< x ) -> x = y ) )  | 
						
						
							| 46 | 
							
								
							 | 
							simpr | 
							 |-  ( ( x .< y /\ y = x ) -> y = x )  | 
						
						
							| 47 | 
							
								46
							 | 
							equcomd | 
							 |-  ( ( x .< y /\ y = x ) -> x = y )  | 
						
						
							| 48 | 
							
								47
							 | 
							a1i | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( x .< y /\ y = x ) -> x = y ) )  | 
						
						
							| 49 | 
							
								
							 | 
							simpl | 
							 |-  ( ( x = y /\ y = x ) -> x = y )  | 
						
						
							| 50 | 
							
								49
							 | 
							a1i | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( x = y /\ y = x ) -> x = y ) )  | 
						
						
							| 51 | 
							
								43 45 48 50
							 | 
							ccased | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( ( x .< y \/ x = y ) /\ ( y .< x \/ y = x ) ) -> x = y ) )  | 
						
						
							| 52 | 
							
								35 38 51
							 | 
							syl2and | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ x e. B /\ y e. B ) -> ( ( x .<_ y /\ y .<_ x ) -> x = y ) )  | 
						
						
							| 53 | 
							
								
							 | 
							simpr1 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> x e. B )  | 
						
						
							| 54 | 
							
								
							 | 
							simpr2 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> y e. B )  | 
						
						
							| 55 | 
							
								53 54 34
							 | 
							syl2anc | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( x .<_ y -> ( x .< y \/ x = y ) ) )  | 
						
						
							| 56 | 
							
								
							 | 
							simpr3 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> z e. B )  | 
						
						
							| 57 | 
							
								1 2 3
							 | 
							pleval2i | 
							 |-  ( ( y e. B /\ z e. B ) -> ( y .<_ z -> ( y .< z \/ y = z ) ) )  | 
						
						
							| 58 | 
							
								54 56 57
							 | 
							syl2anc | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( y .<_ z -> ( y .< z \/ y = z ) ) )  | 
						
						
							| 59 | 
							
								
							 | 
							potr | 
							 |-  ( ( .< Po B /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .< y /\ y .< z ) -> x .< z ) )  | 
						
						
							| 60 | 
							
								39 59
							 | 
							sylan | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .< y /\ y .< z ) -> x .< z ) )  | 
						
						
							| 61 | 
							
								
							 | 
							simpll | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> K e. V )  | 
						
						
							| 62 | 
							
								2 3
							 | 
							pltle | 
							 |-  ( ( K e. V /\ x e. B /\ z e. B ) -> ( x .< z -> x .<_ z ) )  | 
						
						
							| 63 | 
							
								61 53 56 62
							 | 
							syl3anc | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( x .< z -> x .<_ z ) )  | 
						
						
							| 64 | 
							
								60 63
							 | 
							syld | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .< y /\ y .< z ) -> x .<_ z ) )  | 
						
						
							| 65 | 
							
								
							 | 
							breq1 | 
							 |-  ( x = y -> ( x .< z <-> y .< z ) )  | 
						
						
							| 66 | 
							
								65
							 | 
							biimpar | 
							 |-  ( ( x = y /\ y .< z ) -> x .< z )  | 
						
						
							| 67 | 
							
								66 63
							 | 
							syl5 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x = y /\ y .< z ) -> x .<_ z ) )  | 
						
						
							| 68 | 
							
								
							 | 
							breq2 | 
							 |-  ( y = z -> ( x .< y <-> x .< z ) )  | 
						
						
							| 69 | 
							
								68
							 | 
							biimpac | 
							 |-  ( ( x .< y /\ y = z ) -> x .< z )  | 
						
						
							| 70 | 
							
								69 63
							 | 
							syl5 | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .< y /\ y = z ) -> x .<_ z ) )  | 
						
						
							| 71 | 
							
								53 33
							 | 
							syldan | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> x .<_ x )  | 
						
						
							| 72 | 
							
								
							 | 
							eqtr | 
							 |-  ( ( x = y /\ y = z ) -> x = z )  | 
						
						
							| 73 | 
							
								72
							 | 
							breq2d | 
							 |-  ( ( x = y /\ y = z ) -> ( x .<_ x <-> x .<_ z ) )  | 
						
						
							| 74 | 
							
								71 73
							 | 
							syl5ibcom | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x = y /\ y = z ) -> x .<_ z ) )  | 
						
						
							| 75 | 
							
								64 67 70 74
							 | 
							ccased | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( ( x .< y \/ x = y ) /\ ( y .< z \/ y = z ) ) -> x .<_ z ) )  | 
						
						
							| 76 | 
							
								55 58 75
							 | 
							syl2and | 
							 |-  ( ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) /\ ( x e. B /\ y e. B /\ z e. B ) ) -> ( ( x .<_ y /\ y .<_ z ) -> x .<_ z ) )  | 
						
						
							| 77 | 
							
								23 24 25 33 52 76
							 | 
							isposd | 
							 |-  ( ( K e. V /\ ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) -> K e. Poset )  | 
						
						
							| 78 | 
							
								77
							 | 
							ex | 
							 |-  ( K e. V -> ( ( .< Po B /\ ( _I |` B ) C_ .<_ ) -> K e. Poset ) )  | 
						
						
							| 79 | 
							
								22 78
							 | 
							impbid2 | 
							 |-  ( K e. V -> ( K e. Poset <-> ( .< Po B /\ ( _I |` B ) C_ .<_ ) ) )  |