| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj553.1 | 
							 |-  ( ph' <-> ( f ` (/) ) = _pred ( x , A , R ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj553.2 | 
							 |-  ( ps' <-> A. i e. _om ( suc i e. m -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj553.3 | 
							 |-  D = ( _om \ { (/) } ) | 
						
						
							| 4 | 
							
								
							 | 
							bnj553.4 | 
							 |-  G = ( f u. { <. m , U_ y e. ( f ` p ) _pred ( y , A , R ) >. } ) | 
						
						
							| 5 | 
							
								
							 | 
							bnj553.5 | 
							 |-  ( ta <-> ( f Fn m /\ ph' /\ ps' ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj553.6 | 
							 |-  ( si <-> ( m e. D /\ n = suc m /\ p e. m ) )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj553.7 | 
							 |-  C = U_ y e. ( f ` p ) _pred ( y , A , R )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj553.8 | 
							 |-  G = ( f u. { <. m , C >. } ) | 
						
						
							| 9 | 
							
								
							 | 
							bnj553.9 | 
							 |-  B = U_ y e. ( f ` i ) _pred ( y , A , R )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj553.10 | 
							 |-  K = U_ y e. ( G ` i ) _pred ( y , A , R )  | 
						
						
							| 11 | 
							
								
							 | 
							bnj553.11 | 
							 |-  L = U_ y e. ( G ` p ) _pred ( y , A , R )  | 
						
						
							| 12 | 
							
								
							 | 
							bnj553.12 | 
							 |-  ( ( R _FrSe A /\ ta /\ si ) -> G Fn n )  | 
						
						
							| 13 | 
							
								12
							 | 
							fnfund | 
							 |-  ( ( R _FrSe A /\ ta /\ si ) -> Fun G )  | 
						
						
							| 14 | 
							
								
							 | 
							opex | 
							 |-  <. m , C >. e. _V  | 
						
						
							| 15 | 
							
								14
							 | 
							snid | 
							 |-  <. m , C >. e. { <. m , C >. } | 
						
						
							| 16 | 
							
								
							 | 
							elun2 | 
							 |-  ( <. m , C >. e. { <. m , C >. } -> <. m , C >. e. ( f u. { <. m , C >. } ) ) | 
						
						
							| 17 | 
							
								15 16
							 | 
							ax-mp | 
							 |-  <. m , C >. e. ( f u. { <. m , C >. } ) | 
						
						
							| 18 | 
							
								17 8
							 | 
							eleqtrri | 
							 |-  <. m , C >. e. G  | 
						
						
							| 19 | 
							
								
							 | 
							funopfv | 
							 |-  ( Fun G -> ( <. m , C >. e. G -> ( G ` m ) = C ) )  | 
						
						
							| 20 | 
							
								13 18 19
							 | 
							mpisyl | 
							 |-  ( ( R _FrSe A /\ ta /\ si ) -> ( G ` m ) = C )  | 
						
						
							| 21 | 
							
								20
							 | 
							3ad2ant1 | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> ( G ` m ) = C )  | 
						
						
							| 22 | 
							
								
							 | 
							fveq2 | 
							 |-  ( p = i -> ( G ` p ) = ( G ` i ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							bnj1113 | 
							 |-  ( p = i -> U_ y e. ( G ` p ) _pred ( y , A , R ) = U_ y e. ( G ` i ) _pred ( y , A , R ) )  | 
						
						
							| 24 | 
							
								23 11 10
							 | 
							3eqtr4g | 
							 |-  ( p = i -> L = K )  | 
						
						
							| 25 | 
							
								24
							 | 
							3ad2ant3 | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> L = K )  | 
						
						
							| 26 | 
							
								5 9 10 4 12
							 | 
							bnj548 | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m ) -> B = K )  | 
						
						
							| 27 | 
							
								26
							 | 
							3adant3 | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> B = K )  | 
						
						
							| 28 | 
							
								
							 | 
							fveq2 | 
							 |-  ( p = i -> ( f ` p ) = ( f ` i ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							bnj1113 | 
							 |-  ( p = i -> U_ y e. ( f ` p ) _pred ( y , A , R ) = U_ y e. ( f ` i ) _pred ( y , A , R ) )  | 
						
						
							| 30 | 
							
								9 7
							 | 
							eqeq12i | 
							 |-  ( B = C <-> U_ y e. ( f ` i ) _pred ( y , A , R ) = U_ y e. ( f ` p ) _pred ( y , A , R ) )  | 
						
						
							| 31 | 
							
								
							 | 
							eqcom | 
							 |-  ( U_ y e. ( f ` i ) _pred ( y , A , R ) = U_ y e. ( f ` p ) _pred ( y , A , R ) <-> U_ y e. ( f ` p ) _pred ( y , A , R ) = U_ y e. ( f ` i ) _pred ( y , A , R ) )  | 
						
						
							| 32 | 
							
								30 31
							 | 
							bitri | 
							 |-  ( B = C <-> U_ y e. ( f ` p ) _pred ( y , A , R ) = U_ y e. ( f ` i ) _pred ( y , A , R ) )  | 
						
						
							| 33 | 
							
								29 32
							 | 
							sylibr | 
							 |-  ( p = i -> B = C )  | 
						
						
							| 34 | 
							
								33
							 | 
							3ad2ant3 | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> B = C )  | 
						
						
							| 35 | 
							
								25 27 34
							 | 
							3eqtr2rd | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> C = L )  | 
						
						
							| 36 | 
							
								21 35
							 | 
							eqtrd | 
							 |-  ( ( ( R _FrSe A /\ ta /\ si ) /\ i e. m /\ p = i ) -> ( G ` m ) = L )  |