| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							wfrlem13OLD.1 | 
							⊢ 𝑅  We  𝐴  | 
						
						
							| 2 | 
							
								
							 | 
							wfrlem13OLD.2 | 
							⊢ 𝑅  Se  𝐴  | 
						
						
							| 3 | 
							
								
							 | 
							wfrlem13OLD.3 | 
							⊢ 𝐹  =  wrecs ( 𝑅 ,  𝐴 ,  𝐺 )  | 
						
						
							| 4 | 
							
								
							 | 
							wfrlem13OLD.4 | 
							⊢ 𝐶  =  ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } )  | 
						
						
							| 5 | 
							
								1 2 3 4
							 | 
							wfrlem13OLD | 
							⊢ ( 𝑧  ∈  ( 𝐴  ∖  dom  𝐹 )  →  𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } ) )  | 
						
						
							| 6 | 
							
								
							 | 
							elun | 
							⊢ ( 𝑦  ∈  ( dom  𝐹  ∪  { 𝑧 } )  ↔  ( 𝑦  ∈  dom  𝐹  ∨  𝑦  ∈  { 𝑧 } ) )  | 
						
						
							| 7 | 
							
								
							 | 
							velsn | 
							⊢ ( 𝑦  ∈  { 𝑧 }  ↔  𝑦  =  𝑧 )  | 
						
						
							| 8 | 
							
								7
							 | 
							orbi2i | 
							⊢ ( ( 𝑦  ∈  dom  𝐹  ∨  𝑦  ∈  { 𝑧 } )  ↔  ( 𝑦  ∈  dom  𝐹  ∨  𝑦  =  𝑧 ) )  | 
						
						
							| 9 | 
							
								6 8
							 | 
							bitri | 
							⊢ ( 𝑦  ∈  ( dom  𝐹  ∪  { 𝑧 } )  ↔  ( 𝑦  ∈  dom  𝐹  ∨  𝑦  =  𝑧 ) )  | 
						
						
							| 10 | 
							
								1 2 3
							 | 
							wfrlem12OLD | 
							⊢ ( 𝑦  ∈  dom  𝐹  →  ( 𝐹 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) )  | 
						
						
							| 11 | 
							
								
							 | 
							fnfun | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  Fun  𝐶 )  | 
						
						
							| 12 | 
							
								
							 | 
							ssun1 | 
							⊢ 𝐹  ⊆  ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } )  | 
						
						
							| 13 | 
							
								12 4
							 | 
							sseqtrri | 
							⊢ 𝐹  ⊆  𝐶  | 
						
						
							| 14 | 
							
								
							 | 
							funssfv | 
							⊢ ( ( Fun  𝐶  ∧  𝐹  ⊆  𝐶  ∧  𝑦  ∈  dom  𝐹 )  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐹 ‘ 𝑦 ) )  | 
						
						
							| 15 | 
							
								3
							 | 
							wfrdmclOLD | 
							⊢ ( 𝑦  ∈  dom  𝐹  →  Pred ( 𝑅 ,  𝐴 ,  𝑦 )  ⊆  dom  𝐹 )  | 
						
						
							| 16 | 
							
								
							 | 
							fun2ssres | 
							⊢ ( ( Fun  𝐶  ∧  𝐹  ⊆  𝐶  ∧  Pred ( 𝑅 ,  𝐴 ,  𝑦 )  ⊆  dom  𝐹 )  →  ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) )  =  ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  | 
						
						
							| 17 | 
							
								15 16
							 | 
							syl3an3 | 
							⊢ ( ( Fun  𝐶  ∧  𝐹  ⊆  𝐶  ∧  𝑦  ∈  dom  𝐹 )  →  ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) )  =  ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  | 
						
						
							| 18 | 
							
								17
							 | 
							fveq2d | 
							⊢ ( ( Fun  𝐶  ∧  𝐹  ⊆  𝐶  ∧  𝑦  ∈  dom  𝐹 )  →  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) )  | 
						
						
							| 19 | 
							
								14 18
							 | 
							eqeq12d | 
							⊢ ( ( Fun  𝐶  ∧  𝐹  ⊆  𝐶  ∧  𝑦  ∈  dom  𝐹 )  →  ( ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  ↔  ( 𝐹 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 20 | 
							
								13 19
							 | 
							mp3an2 | 
							⊢ ( ( Fun  𝐶  ∧  𝑦  ∈  dom  𝐹 )  →  ( ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  ↔  ( 𝐹 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 21 | 
							
								11 20
							 | 
							sylan | 
							⊢ ( ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  ∧  𝑦  ∈  dom  𝐹 )  →  ( ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  ↔  ( 𝐹 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 22 | 
							
								10 21
							 | 
							imbitrrid | 
							⊢ ( ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  ∧  𝑦  ∈  dom  𝐹 )  →  ( 𝑦  ∈  dom  𝐹  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							ex | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝑦  ∈  dom  𝐹  →  ( 𝑦  ∈  dom  𝐹  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) ) )  | 
						
						
							| 24 | 
							
								23
							 | 
							pm2.43d | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝑦  ∈  dom  𝐹  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 25 | 
							
								
							 | 
							vsnid | 
							⊢ 𝑧  ∈  { 𝑧 }  | 
						
						
							| 26 | 
							
								
							 | 
							elun2 | 
							⊢ ( 𝑧  ∈  { 𝑧 }  →  𝑧  ∈  ( dom  𝐹  ∪  { 𝑧 } ) )  | 
						
						
							| 27 | 
							
								25 26
							 | 
							ax-mp | 
							⊢ 𝑧  ∈  ( dom  𝐹  ∪  { 𝑧 } )  | 
						
						
							| 28 | 
							
								4
							 | 
							reseq1i | 
							⊢ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  =  ( ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } )  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 29 | 
							
								
							 | 
							resundir | 
							⊢ ( ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } )  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  =  ( ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  ∪  ( { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  | 
						
						
							| 30 | 
							
								
							 | 
							wefr | 
							⊢ ( 𝑅  We  𝐴  →  𝑅  Fr  𝐴 )  | 
						
						
							| 31 | 
							
								1 30
							 | 
							ax-mp | 
							⊢ 𝑅  Fr  𝐴  | 
						
						
							| 32 | 
							
								
							 | 
							predfrirr | 
							⊢ ( 𝑅  Fr  𝐴  →  ¬  𝑧  ∈  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 33 | 
							
								
							 | 
							ressnop0 | 
							⊢ ( ¬  𝑧  ∈  Pred ( 𝑅 ,  𝐴 ,  𝑧 )  →  ( { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  =  ∅ )  | 
						
						
							| 34 | 
							
								31 32 33
							 | 
							mp2b | 
							⊢ ( { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  =  ∅  | 
						
						
							| 35 | 
							
								34
							 | 
							uneq2i | 
							⊢ ( ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  ∪  ( { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  =  ( ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  ∪  ∅ )  | 
						
						
							| 36 | 
							
								
							 | 
							un0 | 
							⊢ ( ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  ∪  ∅ )  =  ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 37 | 
							
								35 36
							 | 
							eqtri | 
							⊢ ( ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  ∪  ( { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  =  ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 38 | 
							
								28 29 37
							 | 
							3eqtri | 
							⊢ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  =  ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 39 | 
							
								38
							 | 
							fveq2i | 
							⊢ ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  =  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  | 
						
						
							| 40 | 
							
								39
							 | 
							opeq2i | 
							⊢ 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  =  〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  | 
						
						
							| 41 | 
							
								
							 | 
							opex | 
							⊢ 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  V  | 
						
						
							| 42 | 
							
								41
							 | 
							elsn | 
							⊢ ( 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  ↔  〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  =  〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 )  | 
						
						
							| 43 | 
							
								40 42
							 | 
							mpbir | 
							⊢ 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  | 
						
						
							| 44 | 
							
								
							 | 
							elun2 | 
							⊢ ( 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 }  →  〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } ) )  | 
						
						
							| 45 | 
							
								43 44
							 | 
							ax-mp | 
							⊢ 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  ( 𝐹  ∪  { 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐹  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉 } )  | 
						
						
							| 46 | 
							
								45 4
							 | 
							eleqtrri | 
							⊢ 〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  𝐶  | 
						
						
							| 47 | 
							
								
							 | 
							fnopfvb | 
							⊢ ( ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  ∧  𝑧  ∈  ( dom  𝐹  ∪  { 𝑧 } ) )  →  ( ( 𝐶 ‘ 𝑧 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  ↔  〈 𝑧 ,  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) 〉  ∈  𝐶 ) )  | 
						
						
							| 48 | 
							
								46 47
							 | 
							mpbiri | 
							⊢ ( ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  ∧  𝑧  ∈  ( dom  𝐹  ∪  { 𝑧 } ) )  →  ( 𝐶 ‘ 𝑧 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) )  | 
						
						
							| 49 | 
							
								27 48
							 | 
							mpan2 | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝐶 ‘ 𝑧 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) )  | 
						
						
							| 50 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑦  =  𝑧  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐶 ‘ 𝑧 ) )  | 
						
						
							| 51 | 
							
								
							 | 
							predeq3 | 
							⊢ ( 𝑦  =  𝑧  →  Pred ( 𝑅 ,  𝐴 ,  𝑦 )  =  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) )  | 
						
						
							| 52 | 
							
								51
							 | 
							reseq2d | 
							⊢ ( 𝑦  =  𝑧  →  ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) )  =  ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) )  | 
						
						
							| 53 | 
							
								52
							 | 
							fveq2d | 
							⊢ ( 𝑦  =  𝑧  →  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) )  | 
						
						
							| 54 | 
							
								50 53
							 | 
							eqeq12d | 
							⊢ ( 𝑦  =  𝑧  →  ( ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) )  ↔  ( 𝐶 ‘ 𝑧 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) )  | 
						
						
							| 55 | 
							
								49 54
							 | 
							syl5ibrcom | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝑦  =  𝑧  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 56 | 
							
								24 55
							 | 
							jaod | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( ( 𝑦  ∈  dom  𝐹  ∨  𝑦  =  𝑧 )  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 57 | 
							
								9 56
							 | 
							biimtrid | 
							⊢ ( 𝐶  Fn  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝑦  ∈  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  | 
						
						
							| 58 | 
							
								5 57
							 | 
							syl | 
							⊢ ( 𝑧  ∈  ( 𝐴  ∖  dom  𝐹 )  →  ( 𝑦  ∈  ( dom  𝐹  ∪  { 𝑧 } )  →  ( 𝐶 ‘ 𝑦 )  =  ( 𝐺 ‘ ( 𝐶  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑦 ) ) ) ) )  |