| Step | Hyp | Ref | Expression | 
						
							| 1 |  | satf0suc.s | ⊢ 𝑆  =  ( ∅  Sat  ∅ ) | 
						
							| 2 | 1 | fveq1i | ⊢ ( 𝑆 ‘ suc  𝑁 )  =  ( ( ∅  Sat  ∅ ) ‘ suc  𝑁 ) | 
						
							| 3 | 2 | a1i | ⊢ ( 𝑁  ∈  ω  →  ( 𝑆 ‘ suc  𝑁 )  =  ( ( ∅  Sat  ∅ ) ‘ suc  𝑁 ) ) | 
						
							| 4 |  | omsucelsucb | ⊢ ( 𝑁  ∈  ω  ↔  suc  𝑁  ∈  suc  ω ) | 
						
							| 5 |  | satf0sucom | ⊢ ( suc  𝑁  ∈  suc  ω  →  ( ( ∅  Sat  ∅ ) ‘ suc  𝑁 )  =  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ suc  𝑁 ) ) | 
						
							| 6 | 4 5 | sylbi | ⊢ ( 𝑁  ∈  ω  →  ( ( ∅  Sat  ∅ ) ‘ suc  𝑁 )  =  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ suc  𝑁 ) ) | 
						
							| 7 |  | nnon | ⊢ ( 𝑁  ∈  ω  →  𝑁  ∈  On ) | 
						
							| 8 |  | rdgsuc | ⊢ ( 𝑁  ∈  On  →  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ suc  𝑁 )  =  ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) ) | 
						
							| 9 | 7 8 | syl | ⊢ ( 𝑁  ∈  ω  →  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ suc  𝑁 )  =  ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) ) | 
						
							| 10 |  | elelsuc | ⊢ ( 𝑁  ∈  ω  →  𝑁  ∈  suc  ω ) | 
						
							| 11 |  | satf0sucom | ⊢ ( 𝑁  ∈  suc  ω  →  ( ( ∅  Sat  ∅ ) ‘ 𝑁 )  =  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) | 
						
							| 12 | 10 11 | syl | ⊢ ( 𝑁  ∈  ω  →  ( ( ∅  Sat  ∅ ) ‘ 𝑁 )  =  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) | 
						
							| 13 | 1 | eqcomi | ⊢ ( ∅  Sat  ∅ )  =  𝑆 | 
						
							| 14 | 13 | fveq1i | ⊢ ( ( ∅  Sat  ∅ ) ‘ 𝑁 )  =  ( 𝑆 ‘ 𝑁 ) | 
						
							| 15 | 12 14 | eqtr3di | ⊢ ( 𝑁  ∈  ω  →  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 )  =  ( 𝑆 ‘ 𝑁 ) ) | 
						
							| 16 | 15 | fveq2d | ⊢ ( 𝑁  ∈  ω  →  ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ 𝑁 ) )  =  ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ‘ ( 𝑆 ‘ 𝑁 ) ) ) | 
						
							| 17 |  | eqidd | ⊢ ( 𝑁  ∈  ω  →  ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) )  =  ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ) | 
						
							| 18 |  | id | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  𝑓  =  ( 𝑆 ‘ 𝑁 ) ) | 
						
							| 19 |  | rexeq | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ↔  ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) ) ) ) | 
						
							| 20 | 19 | orbi1d | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  ( ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) )  ↔  ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) ) | 
						
							| 21 | 20 | rexeqbi1dv | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  ( ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) )  ↔  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) ) | 
						
							| 22 | 21 | anbi2d | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  ( ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) )  ↔  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) ) ) | 
						
							| 23 | 22 | opabbidv | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) }  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) | 
						
							| 24 | 18 23 | uneq12d | ⊢ ( 𝑓  =  ( 𝑆 ‘ 𝑁 )  →  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } )  =  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) | 
						
							| 25 | 24 | adantl | ⊢ ( ( 𝑁  ∈  ω  ∧  𝑓  =  ( 𝑆 ‘ 𝑁 ) )  →  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } )  =  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) | 
						
							| 26 |  | fvex | ⊢ ( 𝑆 ‘ 𝑁 )  ∈  V | 
						
							| 27 | 26 | a1i | ⊢ ( 𝑁  ∈  ω  →  ( 𝑆 ‘ 𝑁 )  ∈  V ) | 
						
							| 28 |  | omex | ⊢ ω  ∈  V | 
						
							| 29 |  | satf0suclem | ⊢ ( ( ( 𝑆 ‘ 𝑁 )  ∈  V  ∧  ( 𝑆 ‘ 𝑁 )  ∈  V  ∧  ω  ∈  V )  →  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) }  ∈  V ) | 
						
							| 30 | 26 26 28 29 | mp3an | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) }  ∈  V | 
						
							| 31 | 26 30 | unex | ⊢ ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } )  ∈  V | 
						
							| 32 | 31 | a1i | ⊢ ( 𝑁  ∈  ω  →  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } )  ∈  V ) | 
						
							| 33 | 17 25 27 32 | fvmptd | ⊢ ( 𝑁  ∈  ω  →  ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ‘ ( 𝑆 ‘ 𝑁 ) )  =  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) | 
						
							| 34 | 9 16 33 | 3eqtrd | ⊢ ( 𝑁  ∈  ω  →  ( rec ( ( 𝑓  ∈  V  ↦  ( 𝑓  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  𝑓 ( ∃ 𝑣  ∈  𝑓 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) ,  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑖  ∈  ω ∃ 𝑗  ∈  ω 𝑥  =  ( 𝑖 ∈𝑔 𝑗 ) ) } ) ‘ suc  𝑁 )  =  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) | 
						
							| 35 | 3 6 34 | 3eqtrd | ⊢ ( 𝑁  ∈  ω  →  ( 𝑆 ‘ suc  𝑁 )  =  ( ( 𝑆 ‘ 𝑁 )  ∪  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑦  =  ∅  ∧  ∃ 𝑢  ∈  ( 𝑆 ‘ 𝑁 ) ( ∃ 𝑣  ∈  ( 𝑆 ‘ 𝑁 ) 𝑥  =  ( ( 1st  ‘ 𝑢 ) ⊼𝑔 ( 1st  ‘ 𝑣 ) )  ∨  ∃ 𝑖  ∈  ω 𝑥  =  ∀𝑔 𝑖 ( 1st  ‘ 𝑢 ) ) ) } ) ) |