| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nfwrecsOLD.1 | ⊢ Ⅎ 𝑥 𝑅 | 
						
							| 2 |  | nfwrecsOLD.2 | ⊢ Ⅎ 𝑥 𝐴 | 
						
							| 3 |  | nfwrecsOLD.3 | ⊢ Ⅎ 𝑥 𝐹 | 
						
							| 4 |  | dfwrecsOLD | ⊢ wrecs ( 𝑅 ,  𝐴 ,  𝐹 )  =  ∪  { 𝑓  ∣  ∃ 𝑦 ( 𝑓  Fn  𝑦  ∧  ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 )  ∧  ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) } | 
						
							| 5 |  | nfv | ⊢ Ⅎ 𝑥 𝑓  Fn  𝑦 | 
						
							| 6 |  | nfcv | ⊢ Ⅎ 𝑥 𝑦 | 
						
							| 7 | 6 2 | nfss | ⊢ Ⅎ 𝑥 𝑦  ⊆  𝐴 | 
						
							| 8 |  | nfcv | ⊢ Ⅎ 𝑥 𝑧 | 
						
							| 9 | 1 2 8 | nfpred | ⊢ Ⅎ 𝑥 Pred ( 𝑅 ,  𝐴 ,  𝑧 ) | 
						
							| 10 | 9 6 | nfss | ⊢ Ⅎ 𝑥 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 | 
						
							| 11 | 6 10 | nfralw | ⊢ Ⅎ 𝑥 ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 | 
						
							| 12 | 7 11 | nfan | ⊢ Ⅎ 𝑥 ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 ) | 
						
							| 13 |  | nfcv | ⊢ Ⅎ 𝑥 𝑓 | 
						
							| 14 | 13 9 | nfres | ⊢ Ⅎ 𝑥 ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) | 
						
							| 15 | 3 14 | nffv | ⊢ Ⅎ 𝑥 ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) | 
						
							| 16 | 15 | nfeq2 | ⊢ Ⅎ 𝑥 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) | 
						
							| 17 | 6 16 | nfralw | ⊢ Ⅎ 𝑥 ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) | 
						
							| 18 | 5 12 17 | nf3an | ⊢ Ⅎ 𝑥 ( 𝑓  Fn  𝑦  ∧  ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 )  ∧  ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) | 
						
							| 19 | 18 | nfex | ⊢ Ⅎ 𝑥 ∃ 𝑦 ( 𝑓  Fn  𝑦  ∧  ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 )  ∧  ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) | 
						
							| 20 | 19 | nfab | ⊢ Ⅎ 𝑥 { 𝑓  ∣  ∃ 𝑦 ( 𝑓  Fn  𝑦  ∧  ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 )  ∧  ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) } | 
						
							| 21 | 20 | nfuni | ⊢ Ⅎ 𝑥 ∪  { 𝑓  ∣  ∃ 𝑦 ( 𝑓  Fn  𝑦  ∧  ( 𝑦  ⊆  𝐴  ∧  ∀ 𝑧  ∈  𝑦 Pred ( 𝑅 ,  𝐴 ,  𝑧 )  ⊆  𝑦 )  ∧  ∀ 𝑧  ∈  𝑦 ( 𝑓 ‘ 𝑧 )  =  ( 𝐹 ‘ ( 𝑓  ↾  Pred ( 𝑅 ,  𝐴 ,  𝑧 ) ) ) ) } | 
						
							| 22 | 4 21 | nfcxfr | ⊢ Ⅎ 𝑥 wrecs ( 𝑅 ,  𝐴 ,  𝐹 ) |