| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-ttrcl | ⊢ t++ 𝑅  =  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) } | 
						
							| 2 | 1 | rneqi | ⊢ ran  t++ 𝑅  =  ran  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) } | 
						
							| 3 |  | rnopab | ⊢ ran  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) }  =  { 𝑦  ∣  ∃ 𝑥 ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) } | 
						
							| 4 | 2 3 | eqtri | ⊢ ran  t++ 𝑅  =  { 𝑦  ∣  ∃ 𝑥 ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) } | 
						
							| 5 |  | fveq2 | ⊢ ( 𝑎  =  ∪  𝑛  →  ( 𝑓 ‘ 𝑎 )  =  ( 𝑓 ‘ ∪  𝑛 ) ) | 
						
							| 6 |  | suceq | ⊢ ( 𝑎  =  ∪  𝑛  →  suc  𝑎  =  suc  ∪  𝑛 ) | 
						
							| 7 | 6 | fveq2d | ⊢ ( 𝑎  =  ∪  𝑛  →  ( 𝑓 ‘ suc  𝑎 )  =  ( 𝑓 ‘ suc  ∪  𝑛 ) ) | 
						
							| 8 | 5 7 | breq12d | ⊢ ( 𝑎  =  ∪  𝑛  →  ( ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 )  ↔  ( 𝑓 ‘ ∪  𝑛 ) 𝑅 ( 𝑓 ‘ suc  ∪  𝑛 ) ) ) | 
						
							| 9 |  | simpr3 | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) | 
						
							| 10 |  | df-1o | ⊢ 1o  =  suc  ∅ | 
						
							| 11 | 10 | difeq2i | ⊢ ( ω  ∖  1o )  =  ( ω  ∖  suc  ∅ ) | 
						
							| 12 | 11 | eleq2i | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  ↔  𝑛  ∈  ( ω  ∖  suc  ∅ ) ) | 
						
							| 13 |  | peano1 | ⊢ ∅  ∈  ω | 
						
							| 14 |  | eldifsucnn | ⊢ ( ∅  ∈  ω  →  ( 𝑛  ∈  ( ω  ∖  suc  ∅ )  ↔  ∃ 𝑥  ∈  ( ω  ∖  ∅ ) 𝑛  =  suc  𝑥 ) ) | 
						
							| 15 | 13 14 | ax-mp | ⊢ ( 𝑛  ∈  ( ω  ∖  suc  ∅ )  ↔  ∃ 𝑥  ∈  ( ω  ∖  ∅ ) 𝑛  =  suc  𝑥 ) | 
						
							| 16 |  | dif0 | ⊢ ( ω  ∖  ∅ )  =  ω | 
						
							| 17 | 16 | rexeqi | ⊢ ( ∃ 𝑥  ∈  ( ω  ∖  ∅ ) 𝑛  =  suc  𝑥  ↔  ∃ 𝑥  ∈  ω 𝑛  =  suc  𝑥 ) | 
						
							| 18 | 12 15 17 | 3bitri | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  ↔  ∃ 𝑥  ∈  ω 𝑛  =  suc  𝑥 ) | 
						
							| 19 |  | nnord | ⊢ ( 𝑥  ∈  ω  →  Ord  𝑥 ) | 
						
							| 20 |  | ordunisuc | ⊢ ( Ord  𝑥  →  ∪  suc  𝑥  =  𝑥 ) | 
						
							| 21 | 19 20 | syl | ⊢ ( 𝑥  ∈  ω  →  ∪  suc  𝑥  =  𝑥 ) | 
						
							| 22 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 23 | 22 | sucid | ⊢ 𝑥  ∈  suc  𝑥 | 
						
							| 24 | 21 23 | eqeltrdi | ⊢ ( 𝑥  ∈  ω  →  ∪  suc  𝑥  ∈  suc  𝑥 ) | 
						
							| 25 |  | unieq | ⊢ ( 𝑛  =  suc  𝑥  →  ∪  𝑛  =  ∪  suc  𝑥 ) | 
						
							| 26 |  | id | ⊢ ( 𝑛  =  suc  𝑥  →  𝑛  =  suc  𝑥 ) | 
						
							| 27 | 25 26 | eleq12d | ⊢ ( 𝑛  =  suc  𝑥  →  ( ∪  𝑛  ∈  𝑛  ↔  ∪  suc  𝑥  ∈  suc  𝑥 ) ) | 
						
							| 28 | 24 27 | syl5ibrcom | ⊢ ( 𝑥  ∈  ω  →  ( 𝑛  =  suc  𝑥  →  ∪  𝑛  ∈  𝑛 ) ) | 
						
							| 29 | 28 | rexlimiv | ⊢ ( ∃ 𝑥  ∈  ω 𝑛  =  suc  𝑥  →  ∪  𝑛  ∈  𝑛 ) | 
						
							| 30 | 18 29 | sylbi | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  →  ∪  𝑛  ∈  𝑛 ) | 
						
							| 31 | 30 | adantr | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ∪  𝑛  ∈  𝑛 ) | 
						
							| 32 | 8 9 31 | rspcdva | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ( 𝑓 ‘ ∪  𝑛 ) 𝑅 ( 𝑓 ‘ suc  ∪  𝑛 ) ) | 
						
							| 33 |  | suceq | ⊢ ( ∪  suc  𝑥  =  𝑥  →  suc  ∪  suc  𝑥  =  suc  𝑥 ) | 
						
							| 34 | 21 33 | syl | ⊢ ( 𝑥  ∈  ω  →  suc  ∪  suc  𝑥  =  suc  𝑥 ) | 
						
							| 35 |  | suceq | ⊢ ( ∪  𝑛  =  ∪  suc  𝑥  →  suc  ∪  𝑛  =  suc  ∪  suc  𝑥 ) | 
						
							| 36 | 25 35 | syl | ⊢ ( 𝑛  =  suc  𝑥  →  suc  ∪  𝑛  =  suc  ∪  suc  𝑥 ) | 
						
							| 37 | 36 26 | eqeq12d | ⊢ ( 𝑛  =  suc  𝑥  →  ( suc  ∪  𝑛  =  𝑛  ↔  suc  ∪  suc  𝑥  =  suc  𝑥 ) ) | 
						
							| 38 | 34 37 | syl5ibrcom | ⊢ ( 𝑥  ∈  ω  →  ( 𝑛  =  suc  𝑥  →  suc  ∪  𝑛  =  𝑛 ) ) | 
						
							| 39 | 38 | rexlimiv | ⊢ ( ∃ 𝑥  ∈  ω 𝑛  =  suc  𝑥  →  suc  ∪  𝑛  =  𝑛 ) | 
						
							| 40 | 18 39 | sylbi | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  →  suc  ∪  𝑛  =  𝑛 ) | 
						
							| 41 | 40 | fveq2d | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  →  ( 𝑓 ‘ suc  ∪  𝑛 )  =  ( 𝑓 ‘ 𝑛 ) ) | 
						
							| 42 | 41 | adantr | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ( 𝑓 ‘ suc  ∪  𝑛 )  =  ( 𝑓 ‘ 𝑛 ) ) | 
						
							| 43 |  | simpr2r | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ( 𝑓 ‘ 𝑛 )  =  𝑦 ) | 
						
							| 44 | 42 43 | eqtrd | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ( 𝑓 ‘ suc  ∪  𝑛 )  =  𝑦 ) | 
						
							| 45 | 32 44 | breqtrd | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  ( 𝑓 ‘ ∪  𝑛 ) 𝑅 𝑦 ) | 
						
							| 46 |  | fvex | ⊢ ( 𝑓 ‘ ∪  𝑛 )  ∈  V | 
						
							| 47 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 48 | 46 47 | brelrn | ⊢ ( ( 𝑓 ‘ ∪  𝑛 ) 𝑅 𝑦  →  𝑦  ∈  ran  𝑅 ) | 
						
							| 49 | 45 48 | syl | ⊢ ( ( 𝑛  ∈  ( ω  ∖  1o )  ∧  ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) )  →  𝑦  ∈  ran  𝑅 ) | 
						
							| 50 | 49 | ex | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  →  ( ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) )  →  𝑦  ∈  ran  𝑅 ) ) | 
						
							| 51 | 50 | exlimdv | ⊢ ( 𝑛  ∈  ( ω  ∖  1o )  →  ( ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) )  →  𝑦  ∈  ran  𝑅 ) ) | 
						
							| 52 | 51 | rexlimiv | ⊢ ( ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) )  →  𝑦  ∈  ran  𝑅 ) | 
						
							| 53 | 52 | exlimiv | ⊢ ( ∃ 𝑥 ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) )  →  𝑦  ∈  ran  𝑅 ) | 
						
							| 54 | 53 | abssi | ⊢ { 𝑦  ∣  ∃ 𝑥 ∃ 𝑛  ∈  ( ω  ∖  1o ) ∃ 𝑓 ( 𝑓  Fn  suc  𝑛  ∧  ( ( 𝑓 ‘ ∅ )  =  𝑥  ∧  ( 𝑓 ‘ 𝑛 )  =  𝑦 )  ∧  ∀ 𝑎  ∈  𝑛 ( 𝑓 ‘ 𝑎 ) 𝑅 ( 𝑓 ‘ suc  𝑎 ) ) }  ⊆  ran  𝑅 | 
						
							| 55 | 4 54 | eqsstri | ⊢ ran  t++ 𝑅  ⊆  ran  𝑅 | 
						
							| 56 |  | rnresv | ⊢ ran  ( 𝑅  ↾  V )  =  ran  𝑅 | 
						
							| 57 |  | relres | ⊢ Rel  ( 𝑅  ↾  V ) | 
						
							| 58 |  | ssttrcl | ⊢ ( Rel  ( 𝑅  ↾  V )  →  ( 𝑅  ↾  V )  ⊆  t++ ( 𝑅  ↾  V ) ) | 
						
							| 59 | 57 58 | ax-mp | ⊢ ( 𝑅  ↾  V )  ⊆  t++ ( 𝑅  ↾  V ) | 
						
							| 60 |  | ttrclresv | ⊢ t++ ( 𝑅  ↾  V )  =  t++ 𝑅 | 
						
							| 61 | 59 60 | sseqtri | ⊢ ( 𝑅  ↾  V )  ⊆  t++ 𝑅 | 
						
							| 62 | 61 | rnssi | ⊢ ran  ( 𝑅  ↾  V )  ⊆  ran  t++ 𝑅 | 
						
							| 63 | 56 62 | eqsstrri | ⊢ ran  𝑅  ⊆  ran  t++ 𝑅 | 
						
							| 64 | 55 63 | eqssi | ⊢ ran  t++ 𝑅  =  ran  𝑅 |