| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							uzfbas.1 | 
							 |-  Z = ( ZZ>= ` M )  | 
						
						
							| 2 | 
							
								
							 | 
							zex | 
							 |-  ZZ e. _V  | 
						
						
							| 3 | 
							
								2
							 | 
							pwex | 
							 |-  ~P ZZ e. _V  | 
						
						
							| 4 | 
							
								
							 | 
							uzf | 
							 |-  ZZ>= : ZZ --> ~P ZZ  | 
						
						
							| 5 | 
							
								
							 | 
							frn | 
							 |-  ( ZZ>= : ZZ --> ~P ZZ -> ran ZZ>= C_ ~P ZZ )  | 
						
						
							| 6 | 
							
								4 5
							 | 
							ax-mp | 
							 |-  ran ZZ>= C_ ~P ZZ  | 
						
						
							| 7 | 
							
								3 6
							 | 
							ssexi | 
							 |-  ran ZZ>= e. _V  | 
						
						
							| 8 | 
							
								1
							 | 
							fvexi | 
							 |-  Z e. _V  | 
						
						
							| 9 | 
							
								
							 | 
							restval | 
							 |-  ( ( ran ZZ>= e. _V /\ Z e. _V ) -> ( ran ZZ>= |`t Z ) = ran ( x e. ran ZZ>= |-> ( x i^i Z ) ) )  | 
						
						
							| 10 | 
							
								7 8 9
							 | 
							mp2an | 
							 |-  ( ran ZZ>= |`t Z ) = ran ( x e. ran ZZ>= |-> ( x i^i Z ) )  | 
						
						
							| 11 | 
							
								1
							 | 
							ineq2i | 
							 |-  ( ( ZZ>= ` y ) i^i Z ) = ( ( ZZ>= ` y ) i^i ( ZZ>= ` M ) )  | 
						
						
							| 12 | 
							
								
							 | 
							uzin | 
							 |-  ( ( y e. ZZ /\ M e. ZZ ) -> ( ( ZZ>= ` y ) i^i ( ZZ>= ` M ) ) = ( ZZ>= ` if ( y <_ M , M , y ) ) )  | 
						
						
							| 13 | 
							
								12
							 | 
							ancoms | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> ( ( ZZ>= ` y ) i^i ( ZZ>= ` M ) ) = ( ZZ>= ` if ( y <_ M , M , y ) ) )  | 
						
						
							| 14 | 
							
								11 13
							 | 
							eqtrid | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> ( ( ZZ>= ` y ) i^i Z ) = ( ZZ>= ` if ( y <_ M , M , y ) ) )  | 
						
						
							| 15 | 
							
								
							 | 
							ffn | 
							 |-  ( ZZ>= : ZZ --> ~P ZZ -> ZZ>= Fn ZZ )  | 
						
						
							| 16 | 
							
								4 15
							 | 
							ax-mp | 
							 |-  ZZ>= Fn ZZ  | 
						
						
							| 17 | 
							
								
							 | 
							uzssz | 
							 |-  ( ZZ>= ` M ) C_ ZZ  | 
						
						
							| 18 | 
							
								1 17
							 | 
							eqsstri | 
							 |-  Z C_ ZZ  | 
						
						
							| 19 | 
							
								
							 | 
							ifcl | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> if ( y <_ M , M , y ) e. ZZ )  | 
						
						
							| 20 | 
							
								
							 | 
							uzid | 
							 |-  ( if ( y <_ M , M , y ) e. ZZ -> if ( y <_ M , M , y ) e. ( ZZ>= ` if ( y <_ M , M , y ) ) )  | 
						
						
							| 21 | 
							
								19 20
							 | 
							syl | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> if ( y <_ M , M , y ) e. ( ZZ>= ` if ( y <_ M , M , y ) ) )  | 
						
						
							| 22 | 
							
								21 14
							 | 
							eleqtrrd | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> if ( y <_ M , M , y ) e. ( ( ZZ>= ` y ) i^i Z ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							elin2d | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> if ( y <_ M , M , y ) e. Z )  | 
						
						
							| 24 | 
							
								
							 | 
							fnfvima | 
							 |-  ( ( ZZ>= Fn ZZ /\ Z C_ ZZ /\ if ( y <_ M , M , y ) e. Z ) -> ( ZZ>= ` if ( y <_ M , M , y ) ) e. ( ZZ>= " Z ) )  | 
						
						
							| 25 | 
							
								16 18 23 24
							 | 
							mp3an12i | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> ( ZZ>= ` if ( y <_ M , M , y ) ) e. ( ZZ>= " Z ) )  | 
						
						
							| 26 | 
							
								14 25
							 | 
							eqeltrd | 
							 |-  ( ( M e. ZZ /\ y e. ZZ ) -> ( ( ZZ>= ` y ) i^i Z ) e. ( ZZ>= " Z ) )  | 
						
						
							| 27 | 
							
								26
							 | 
							ralrimiva | 
							 |-  ( M e. ZZ -> A. y e. ZZ ( ( ZZ>= ` y ) i^i Z ) e. ( ZZ>= " Z ) )  | 
						
						
							| 28 | 
							
								
							 | 
							ineq1 | 
							 |-  ( x = ( ZZ>= ` y ) -> ( x i^i Z ) = ( ( ZZ>= ` y ) i^i Z ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							eleq1d | 
							 |-  ( x = ( ZZ>= ` y ) -> ( ( x i^i Z ) e. ( ZZ>= " Z ) <-> ( ( ZZ>= ` y ) i^i Z ) e. ( ZZ>= " Z ) ) )  | 
						
						
							| 30 | 
							
								29
							 | 
							ralrn | 
							 |-  ( ZZ>= Fn ZZ -> ( A. x e. ran ZZ>= ( x i^i Z ) e. ( ZZ>= " Z ) <-> A. y e. ZZ ( ( ZZ>= ` y ) i^i Z ) e. ( ZZ>= " Z ) ) )  | 
						
						
							| 31 | 
							
								16 30
							 | 
							ax-mp | 
							 |-  ( A. x e. ran ZZ>= ( x i^i Z ) e. ( ZZ>= " Z ) <-> A. y e. ZZ ( ( ZZ>= ` y ) i^i Z ) e. ( ZZ>= " Z ) )  | 
						
						
							| 32 | 
							
								27 31
							 | 
							sylibr | 
							 |-  ( M e. ZZ -> A. x e. ran ZZ>= ( x i^i Z ) e. ( ZZ>= " Z ) )  | 
						
						
							| 33 | 
							
								
							 | 
							eqid | 
							 |-  ( x e. ran ZZ>= |-> ( x i^i Z ) ) = ( x e. ran ZZ>= |-> ( x i^i Z ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							fmpt | 
							 |-  ( A. x e. ran ZZ>= ( x i^i Z ) e. ( ZZ>= " Z ) <-> ( x e. ran ZZ>= |-> ( x i^i Z ) ) : ran ZZ>= --> ( ZZ>= " Z ) )  | 
						
						
							| 35 | 
							
								32 34
							 | 
							sylib | 
							 |-  ( M e. ZZ -> ( x e. ran ZZ>= |-> ( x i^i Z ) ) : ran ZZ>= --> ( ZZ>= " Z ) )  | 
						
						
							| 36 | 
							
								35
							 | 
							frnd | 
							 |-  ( M e. ZZ -> ran ( x e. ran ZZ>= |-> ( x i^i Z ) ) C_ ( ZZ>= " Z ) )  | 
						
						
							| 37 | 
							
								10 36
							 | 
							eqsstrid | 
							 |-  ( M e. ZZ -> ( ran ZZ>= |`t Z ) C_ ( ZZ>= " Z ) )  | 
						
						
							| 38 | 
							
								1
							 | 
							uztrn2 | 
							 |-  ( ( x e. Z /\ y e. ( ZZ>= ` x ) ) -> y e. Z )  | 
						
						
							| 39 | 
							
								38
							 | 
							ex | 
							 |-  ( x e. Z -> ( y e. ( ZZ>= ` x ) -> y e. Z ) )  | 
						
						
							| 40 | 
							
								39
							 | 
							ssrdv | 
							 |-  ( x e. Z -> ( ZZ>= ` x ) C_ Z )  | 
						
						
							| 41 | 
							
								40
							 | 
							adantl | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> ( ZZ>= ` x ) C_ Z )  | 
						
						
							| 42 | 
							
								
							 | 
							dfss2 | 
							 |-  ( ( ZZ>= ` x ) C_ Z <-> ( ( ZZ>= ` x ) i^i Z ) = ( ZZ>= ` x ) )  | 
						
						
							| 43 | 
							
								41 42
							 | 
							sylib | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> ( ( ZZ>= ` x ) i^i Z ) = ( ZZ>= ` x ) )  | 
						
						
							| 44 | 
							
								18
							 | 
							sseli | 
							 |-  ( x e. Z -> x e. ZZ )  | 
						
						
							| 45 | 
							
								44
							 | 
							adantl | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> x e. ZZ )  | 
						
						
							| 46 | 
							
								
							 | 
							fnfvelrn | 
							 |-  ( ( ZZ>= Fn ZZ /\ x e. ZZ ) -> ( ZZ>= ` x ) e. ran ZZ>= )  | 
						
						
							| 47 | 
							
								16 45 46
							 | 
							sylancr | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> ( ZZ>= ` x ) e. ran ZZ>= )  | 
						
						
							| 48 | 
							
								
							 | 
							elrestr | 
							 |-  ( ( ran ZZ>= e. _V /\ Z e. _V /\ ( ZZ>= ` x ) e. ran ZZ>= ) -> ( ( ZZ>= ` x ) i^i Z ) e. ( ran ZZ>= |`t Z ) )  | 
						
						
							| 49 | 
							
								7 8 47 48
							 | 
							mp3an12i | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> ( ( ZZ>= ` x ) i^i Z ) e. ( ran ZZ>= |`t Z ) )  | 
						
						
							| 50 | 
							
								43 49
							 | 
							eqeltrrd | 
							 |-  ( ( M e. ZZ /\ x e. Z ) -> ( ZZ>= ` x ) e. ( ran ZZ>= |`t Z ) )  | 
						
						
							| 51 | 
							
								50
							 | 
							ralrimiva | 
							 |-  ( M e. ZZ -> A. x e. Z ( ZZ>= ` x ) e. ( ran ZZ>= |`t Z ) )  | 
						
						
							| 52 | 
							
								
							 | 
							ffun | 
							 |-  ( ZZ>= : ZZ --> ~P ZZ -> Fun ZZ>= )  | 
						
						
							| 53 | 
							
								4 52
							 | 
							ax-mp | 
							 |-  Fun ZZ>=  | 
						
						
							| 54 | 
							
								4
							 | 
							fdmi | 
							 |-  dom ZZ>= = ZZ  | 
						
						
							| 55 | 
							
								18 54
							 | 
							sseqtrri | 
							 |-  Z C_ dom ZZ>=  | 
						
						
							| 56 | 
							
								
							 | 
							funimass4 | 
							 |-  ( ( Fun ZZ>= /\ Z C_ dom ZZ>= ) -> ( ( ZZ>= " Z ) C_ ( ran ZZ>= |`t Z ) <-> A. x e. Z ( ZZ>= ` x ) e. ( ran ZZ>= |`t Z ) ) )  | 
						
						
							| 57 | 
							
								53 55 56
							 | 
							mp2an | 
							 |-  ( ( ZZ>= " Z ) C_ ( ran ZZ>= |`t Z ) <-> A. x e. Z ( ZZ>= ` x ) e. ( ran ZZ>= |`t Z ) )  | 
						
						
							| 58 | 
							
								51 57
							 | 
							sylibr | 
							 |-  ( M e. ZZ -> ( ZZ>= " Z ) C_ ( ran ZZ>= |`t Z ) )  | 
						
						
							| 59 | 
							
								37 58
							 | 
							eqssd | 
							 |-  ( M e. ZZ -> ( ran ZZ>= |`t Z ) = ( ZZ>= " Z ) )  |