| 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 |  | oemapval.f | ⊢ ( 𝜑  →  𝐹  ∈  𝑆 ) | 
						
							| 6 |  | oemapval.g | ⊢ ( 𝜑  →  𝐺  ∈  𝑆 ) | 
						
							| 7 |  | fveq1 | ⊢ ( 𝑥  =  𝐹  →  ( 𝑥 ‘ 𝑧 )  =  ( 𝐹 ‘ 𝑧 ) ) | 
						
							| 8 |  | fveq1 | ⊢ ( 𝑦  =  𝐺  →  ( 𝑦 ‘ 𝑧 )  =  ( 𝐺 ‘ 𝑧 ) ) | 
						
							| 9 |  | eleq12 | ⊢ ( ( ( 𝑥 ‘ 𝑧 )  =  ( 𝐹 ‘ 𝑧 )  ∧  ( 𝑦 ‘ 𝑧 )  =  ( 𝐺 ‘ 𝑧 ) )  →  ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ↔  ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 ) ) ) | 
						
							| 10 | 7 8 9 | syl2an | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ↔  ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 ) ) ) | 
						
							| 11 |  | fveq1 | ⊢ ( 𝑥  =  𝐹  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝐹 ‘ 𝑤 ) ) | 
						
							| 12 |  | fveq1 | ⊢ ( 𝑦  =  𝐺  →  ( 𝑦 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) | 
						
							| 13 | 11 12 | eqeqan12d | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 )  ↔  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) | 
						
							| 14 | 13 | imbi2d | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) )  ↔  ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) | 
						
							| 15 | 14 | ralbidv | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) )  ↔  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) | 
						
							| 16 | 10 15 | anbi12d | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) )  ↔  ( ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) ) | 
						
							| 17 | 16 | rexbidv | ⊢ ( ( 𝑥  =  𝐹  ∧  𝑦  =  𝐺 )  →  ( ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) )  ↔  ∃ 𝑧  ∈  𝐵 ( ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) ) | 
						
							| 18 | 17 4 | brabga | ⊢ ( ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆 )  →  ( 𝐹 𝑇 𝐺  ↔  ∃ 𝑧  ∈  𝐵 ( ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) ) | 
						
							| 19 | 5 6 18 | syl2anc | ⊢ ( 𝜑  →  ( 𝐹 𝑇 𝐺  ↔  ∃ 𝑧  ∈  𝐵 ( ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐺 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝐹 ‘ 𝑤 )  =  ( 𝐺 ‘ 𝑤 ) ) ) ) ) |