| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cantnfs.s | ⊢ 𝑆  =  dom  ( 𝐴  CNF  𝐵 ) | 
						
							| 2 |  | cantnfs.a | ⊢ ( 𝜑  →  𝐴  ∈  On ) | 
						
							| 3 |  | cantnfs.b | ⊢ ( 𝜑  →  𝐵  ∈  On ) | 
						
							| 4 |  | oemapval.t | ⊢ 𝑇  =  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) } | 
						
							| 5 |  | eloni | ⊢ ( 𝐵  ∈  On  →  Ord  𝐵 ) | 
						
							| 6 |  | ordwe | ⊢ ( Ord  𝐵  →   E   We  𝐵 ) | 
						
							| 7 |  | weso | ⊢ (  E   We  𝐵  →   E   Or  𝐵 ) | 
						
							| 8 | 3 5 6 7 | 4syl | ⊢ ( 𝜑  →   E   Or  𝐵 ) | 
						
							| 9 |  | cnvso | ⊢ (  E   Or  𝐵  ↔  ◡  E   Or  𝐵 ) | 
						
							| 10 | 8 9 | sylib | ⊢ ( 𝜑  →  ◡  E   Or  𝐵 ) | 
						
							| 11 |  | eloni | ⊢ ( 𝐴  ∈  On  →  Ord  𝐴 ) | 
						
							| 12 |  | ordwe | ⊢ ( Ord  𝐴  →   E   We  𝐴 ) | 
						
							| 13 |  | weso | ⊢ (  E   We  𝐴  →   E   Or  𝐴 ) | 
						
							| 14 | 2 11 12 13 | 4syl | ⊢ ( 𝜑  →   E   Or  𝐴 ) | 
						
							| 15 |  | fvex | ⊢ ( 𝑦 ‘ 𝑧 )  ∈  V | 
						
							| 16 | 15 | epeli | ⊢ ( ( 𝑥 ‘ 𝑧 )  E  ( 𝑦 ‘ 𝑧 )  ↔  ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 ) ) | 
						
							| 17 |  | vex | ⊢ 𝑤  ∈  V | 
						
							| 18 |  | vex | ⊢ 𝑧  ∈  V | 
						
							| 19 | 17 18 | brcnv | ⊢ ( 𝑤 ◡  E  𝑧  ↔  𝑧  E  𝑤 ) | 
						
							| 20 |  | epel | ⊢ ( 𝑧  E  𝑤  ↔  𝑧  ∈  𝑤 ) | 
						
							| 21 | 19 20 | bitri | ⊢ ( 𝑤 ◡  E  𝑧  ↔  𝑧  ∈  𝑤 ) | 
						
							| 22 | 21 | imbi1i | ⊢ ( ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) )  ↔  ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) | 
						
							| 23 | 22 | ralbii | ⊢ ( ∀ 𝑤  ∈  𝐵 ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) )  ↔  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) | 
						
							| 24 | 16 23 | anbi12i | ⊢ ( ( ( 𝑥 ‘ 𝑧 )  E  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) )  ↔  ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) ) | 
						
							| 25 | 24 | rexbii | ⊢ ( ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  E  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) )  ↔  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) ) | 
						
							| 26 | 25 | opabbii | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  E  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) }  =  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) } | 
						
							| 27 | 4 26 | eqtr4i | ⊢ 𝑇  =  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  E  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑤 ◡  E  𝑧  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) } | 
						
							| 28 |  | breq1 | ⊢ ( 𝑔  =  𝑥  →  ( 𝑔  finSupp  ∅  ↔  𝑥  finSupp  ∅ ) ) | 
						
							| 29 | 28 | cbvrabv | ⊢ { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ }  =  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } | 
						
							| 30 | 27 29 | wemapso2 | ⊢ ( ( 𝐵  ∈  On  ∧  ◡  E   Or  𝐵  ∧   E   Or  𝐴 )  →  𝑇  Or  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) | 
						
							| 31 | 3 10 14 30 | syl3anc | ⊢ ( 𝜑  →  𝑇  Or  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) | 
						
							| 32 |  | eqid | ⊢ { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ }  =  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } | 
						
							| 33 | 32 2 3 | cantnfdm | ⊢ ( 𝜑  →  dom  ( 𝐴  CNF  𝐵 )  =  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) | 
						
							| 34 | 1 33 | eqtrid | ⊢ ( 𝜑  →  𝑆  =  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) | 
						
							| 35 |  | soeq2 | ⊢ ( 𝑆  =  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ }  →  ( 𝑇  Or  𝑆  ↔  𝑇  Or  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) ) | 
						
							| 36 | 34 35 | syl | ⊢ ( 𝜑  →  ( 𝑇  Or  𝑆  ↔  𝑇  Or  { 𝑔  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑔  finSupp  ∅ } ) ) | 
						
							| 37 | 31 36 | mpbird | ⊢ ( 𝜑  →  𝑇  Or  𝑆 ) |