| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1253.1 | 
							 |-  B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) } | 
						
						
							| 2 | 
							
								
							 | 
							bnj1253.2 | 
							 |-  Y = <. x , ( f |` _pred ( x , A , R ) ) >.  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1253.3 | 
							 |-  C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) } | 
						
						
							| 4 | 
							
								
							 | 
							bnj1253.4 | 
							 |-  D = ( dom g i^i dom h )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1253.5 | 
							 |-  E = { x e. D | ( g ` x ) =/= ( h ` x ) } | 
						
						
							| 6 | 
							
								
							 | 
							bnj1253.6 | 
							 |-  ( ph <-> ( R _FrSe A /\ g e. C /\ h e. C /\ ( g |` D ) =/= ( h |` D ) ) )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj1253.7 | 
							 |-  ( ps <-> ( ph /\ x e. E /\ A. y e. E -. y R x ) )  | 
						
						
							| 8 | 
							
								6
							 | 
							bnj1254 | 
							 |-  ( ph -> ( g |` D ) =/= ( h |` D ) )  | 
						
						
							| 9 | 
							
								1 2 3 4 5 6 7
							 | 
							bnj1256 | 
							 |-  ( ph -> E. d e. B g Fn d )  | 
						
						
							| 10 | 
							
								4
							 | 
							bnj1292 | 
							 |-  D C_ dom g  | 
						
						
							| 11 | 
							
								
							 | 
							fndm | 
							 |-  ( g Fn d -> dom g = d )  | 
						
						
							| 12 | 
							
								10 11
							 | 
							sseqtrid | 
							 |-  ( g Fn d -> D C_ d )  | 
						
						
							| 13 | 
							
								
							 | 
							fnssres | 
							 |-  ( ( g Fn d /\ D C_ d ) -> ( g |` D ) Fn D )  | 
						
						
							| 14 | 
							
								12 13
							 | 
							mpdan | 
							 |-  ( g Fn d -> ( g |` D ) Fn D )  | 
						
						
							| 15 | 
							
								9 14
							 | 
							bnj31 | 
							 |-  ( ph -> E. d e. B ( g |` D ) Fn D )  | 
						
						
							| 16 | 
							
								15
							 | 
							bnj1265 | 
							 |-  ( ph -> ( g |` D ) Fn D )  | 
						
						
							| 17 | 
							
								1 2 3 4 5 6 7
							 | 
							bnj1259 | 
							 |-  ( ph -> E. d e. B h Fn d )  | 
						
						
							| 18 | 
							
								4
							 | 
							bnj1293 | 
							 |-  D C_ dom h  | 
						
						
							| 19 | 
							
								
							 | 
							fndm | 
							 |-  ( h Fn d -> dom h = d )  | 
						
						
							| 20 | 
							
								18 19
							 | 
							sseqtrid | 
							 |-  ( h Fn d -> D C_ d )  | 
						
						
							| 21 | 
							
								
							 | 
							fnssres | 
							 |-  ( ( h Fn d /\ D C_ d ) -> ( h |` D ) Fn D )  | 
						
						
							| 22 | 
							
								20 21
							 | 
							mpdan | 
							 |-  ( h Fn d -> ( h |` D ) Fn D )  | 
						
						
							| 23 | 
							
								17 22
							 | 
							bnj31 | 
							 |-  ( ph -> E. d e. B ( h |` D ) Fn D )  | 
						
						
							| 24 | 
							
								23
							 | 
							bnj1265 | 
							 |-  ( ph -> ( h |` D ) Fn D )  | 
						
						
							| 25 | 
							
								
							 | 
							ssid | 
							 |-  D C_ D  | 
						
						
							| 26 | 
							
								
							 | 
							fvreseq | 
							 |-  ( ( ( ( g |` D ) Fn D /\ ( h |` D ) Fn D ) /\ D C_ D ) -> ( ( ( g |` D ) |` D ) = ( ( h |` D ) |` D ) <-> A. x e. D ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) )  | 
						
						
							| 27 | 
							
								25 26
							 | 
							mpan2 | 
							 |-  ( ( ( g |` D ) Fn D /\ ( h |` D ) Fn D ) -> ( ( ( g |` D ) |` D ) = ( ( h |` D ) |` D ) <-> A. x e. D ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) )  | 
						
						
							| 28 | 
							
								16 24 27
							 | 
							syl2anc | 
							 |-  ( ph -> ( ( ( g |` D ) |` D ) = ( ( h |` D ) |` D ) <-> A. x e. D ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) )  | 
						
						
							| 29 | 
							
								
							 | 
							residm | 
							 |-  ( ( g |` D ) |` D ) = ( g |` D )  | 
						
						
							| 30 | 
							
								
							 | 
							residm | 
							 |-  ( ( h |` D ) |` D ) = ( h |` D )  | 
						
						
							| 31 | 
							
								29 30
							 | 
							eqeq12i | 
							 |-  ( ( ( g |` D ) |` D ) = ( ( h |` D ) |` D ) <-> ( g |` D ) = ( h |` D ) )  | 
						
						
							| 32 | 
							
								
							 | 
							df-ral | 
							 |-  ( A. x e. D ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) <-> A. x ( x e. D -> ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) )  | 
						
						
							| 33 | 
							
								28 31 32
							 | 
							3bitr3g | 
							 |-  ( ph -> ( ( g |` D ) = ( h |` D ) <-> A. x ( x e. D -> ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) ) )  | 
						
						
							| 34 | 
							
								
							 | 
							fvres | 
							 |-  ( x e. D -> ( ( g |` D ) ` x ) = ( g ` x ) )  | 
						
						
							| 35 | 
							
								
							 | 
							fvres | 
							 |-  ( x e. D -> ( ( h |` D ) ` x ) = ( h ` x ) )  | 
						
						
							| 36 | 
							
								34 35
							 | 
							eqeq12d | 
							 |-  ( x e. D -> ( ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) <-> ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 37 | 
							
								36
							 | 
							pm5.74i | 
							 |-  ( ( x e. D -> ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) <-> ( x e. D -> ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 38 | 
							
								37
							 | 
							albii | 
							 |-  ( A. x ( x e. D -> ( ( g |` D ) ` x ) = ( ( h |` D ) ` x ) ) <-> A. x ( x e. D -> ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 39 | 
							
								33 38
							 | 
							bitrdi | 
							 |-  ( ph -> ( ( g |` D ) = ( h |` D ) <-> A. x ( x e. D -> ( g ` x ) = ( h ` x ) ) ) )  | 
						
						
							| 40 | 
							
								39
							 | 
							necon3abid | 
							 |-  ( ph -> ( ( g |` D ) =/= ( h |` D ) <-> -. A. x ( x e. D -> ( g ` x ) = ( h ` x ) ) ) )  | 
						
						
							| 41 | 
							
								
							 | 
							df-rex | 
							 |-  ( E. x e. D ( g ` x ) =/= ( h ` x ) <-> E. x ( x e. D /\ ( g ` x ) =/= ( h ` x ) ) )  | 
						
						
							| 42 | 
							
								
							 | 
							pm4.61 | 
							 |-  ( -. ( x e. D -> ( g ` x ) = ( h ` x ) ) <-> ( x e. D /\ -. ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 43 | 
							
								
							 | 
							df-ne | 
							 |-  ( ( g ` x ) =/= ( h ` x ) <-> -. ( g ` x ) = ( h ` x ) )  | 
						
						
							| 44 | 
							
								43
							 | 
							anbi2i | 
							 |-  ( ( x e. D /\ ( g ` x ) =/= ( h ` x ) ) <-> ( x e. D /\ -. ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 45 | 
							
								42 44
							 | 
							bitr4i | 
							 |-  ( -. ( x e. D -> ( g ` x ) = ( h ` x ) ) <-> ( x e. D /\ ( g ` x ) =/= ( h ` x ) ) )  | 
						
						
							| 46 | 
							
								45
							 | 
							exbii | 
							 |-  ( E. x -. ( x e. D -> ( g ` x ) = ( h ` x ) ) <-> E. x ( x e. D /\ ( g ` x ) =/= ( h ` x ) ) )  | 
						
						
							| 47 | 
							
								
							 | 
							exnal | 
							 |-  ( E. x -. ( x e. D -> ( g ` x ) = ( h ` x ) ) <-> -. A. x ( x e. D -> ( g ` x ) = ( h ` x ) ) )  | 
						
						
							| 48 | 
							
								41 46 47
							 | 
							3bitr2ri | 
							 |-  ( -. A. x ( x e. D -> ( g ` x ) = ( h ` x ) ) <-> E. x e. D ( g ` x ) =/= ( h ` x ) )  | 
						
						
							| 49 | 
							
								40 48
							 | 
							bitrdi | 
							 |-  ( ph -> ( ( g |` D ) =/= ( h |` D ) <-> E. x e. D ( g ` x ) =/= ( h ` x ) ) )  | 
						
						
							| 50 | 
							
								8 49
							 | 
							mpbid | 
							 |-  ( ph -> E. x e. D ( g ` x ) =/= ( h ` x ) )  | 
						
						
							| 51 | 
							
								5
							 | 
							neeq1i | 
							 |-  ( E =/= (/) <-> { x e. D | ( g ` x ) =/= ( h ` x ) } =/= (/) ) | 
						
						
							| 52 | 
							
								
							 | 
							rabn0 | 
							 |-  ( { x e. D | ( g ` x ) =/= ( h ` x ) } =/= (/) <-> E. x e. D ( g ` x ) =/= ( h ` x ) ) | 
						
						
							| 53 | 
							
								51 52
							 | 
							bitri | 
							 |-  ( E =/= (/) <-> E. x e. D ( g ` x ) =/= ( h ` x ) )  | 
						
						
							| 54 | 
							
								50 53
							 | 
							sylibr | 
							 |-  ( ph -> E =/= (/) )  |