| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ptpjpre1.1 | ⊢ 𝑋  =  X 𝑘  ∈  𝐴 ∪  ( 𝐹 ‘ 𝑘 ) | 
						
							| 2 |  | fveq2 | ⊢ ( 𝑘  =  𝐼  →  ( 𝑤 ‘ 𝑘 )  =  ( 𝑤 ‘ 𝐼 ) ) | 
						
							| 3 |  | fveq2 | ⊢ ( 𝑘  =  𝐼  →  ( 𝐹 ‘ 𝑘 )  =  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 4 | 3 | unieqd | ⊢ ( 𝑘  =  𝐼  →  ∪  ( 𝐹 ‘ 𝑘 )  =  ∪  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 5 | 2 4 | eleq12d | ⊢ ( 𝑘  =  𝐼  →  ( ( 𝑤 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ↔  ( 𝑤 ‘ 𝐼 )  ∈  ∪  ( 𝐹 ‘ 𝐼 ) ) ) | 
						
							| 6 |  | vex | ⊢ 𝑤  ∈  V | 
						
							| 7 | 6 | elixp | ⊢ ( 𝑤  ∈  X 𝑘  ∈  𝐴 ∪  ( 𝐹 ‘ 𝑘 )  ↔  ( 𝑤  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑤 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 8 | 7 | simprbi | ⊢ ( 𝑤  ∈  X 𝑘  ∈  𝐴 ∪  ( 𝐹 ‘ 𝑘 )  →  ∀ 𝑘  ∈  𝐴 ( 𝑤 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 9 | 8 1 | eleq2s | ⊢ ( 𝑤  ∈  𝑋  →  ∀ 𝑘  ∈  𝐴 ( 𝑤 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 10 | 9 | adantl | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  𝑤  ∈  𝑋 )  →  ∀ 𝑘  ∈  𝐴 ( 𝑤 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 11 |  | simplrl | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  𝑤  ∈  𝑋 )  →  𝐼  ∈  𝐴 ) | 
						
							| 12 | 5 10 11 | rspcdva | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  𝑤  ∈  𝑋 )  →  ( 𝑤 ‘ 𝐼 )  ∈  ∪  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 13 | 12 | fmpttd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) : 𝑋 ⟶ ∪  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 14 |  | ffn | ⊢ ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) : 𝑋 ⟶ ∪  ( 𝐹 ‘ 𝐼 )  →  ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  Fn  𝑋 ) | 
						
							| 15 |  | elpreima | ⊢ ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  Fn  𝑋  →  ( 𝑧  ∈  ( ◡ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  “  𝑈 )  ↔  ( 𝑧  ∈  𝑋  ∧  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈 ) ) ) | 
						
							| 16 | 13 14 15 | 3syl | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( 𝑧  ∈  ( ◡ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  “  𝑈 )  ↔  ( 𝑧  ∈  𝑋  ∧  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈 ) ) ) | 
						
							| 17 |  | fveq1 | ⊢ ( 𝑤  =  𝑧  →  ( 𝑤 ‘ 𝐼 )  =  ( 𝑧 ‘ 𝐼 ) ) | 
						
							| 18 |  | eqid | ⊢ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  =  ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) | 
						
							| 19 |  | fvex | ⊢ ( 𝑧 ‘ 𝐼 )  ∈  V | 
						
							| 20 | 17 18 19 | fvmpt | ⊢ ( 𝑧  ∈  𝑋  →  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  =  ( 𝑧 ‘ 𝐼 ) ) | 
						
							| 21 | 20 | eleq1d | ⊢ ( 𝑧  ∈  𝑋  →  ( ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈  ↔  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 22 | 21 | pm5.32i | ⊢ ( ( 𝑧  ∈  𝑋  ∧  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈 )  ↔  ( 𝑧  ∈  𝑋  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 23 | 1 | eleq2i | ⊢ ( 𝑧  ∈  𝑋  ↔  𝑧  ∈  X 𝑘  ∈  𝐴 ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 24 |  | vex | ⊢ 𝑧  ∈  V | 
						
							| 25 | 24 | elixp | ⊢ ( 𝑧  ∈  X 𝑘  ∈  𝐴 ∪  ( 𝐹 ‘ 𝑘 )  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 26 | 23 25 | bitri | ⊢ ( 𝑧  ∈  𝑋  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 27 | 26 | anbi1i | ⊢ ( ( 𝑧  ∈  𝑋  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  ↔  ( ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 28 |  | anass | ⊢ ( ( ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  ↔  ( 𝑧  Fn  𝐴  ∧  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) ) | 
						
							| 29 | 27 28 | bitri | ⊢ ( ( 𝑧  ∈  𝑋  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  ↔  ( 𝑧  Fn  𝐴  ∧  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) ) | 
						
							| 30 | 22 29 | bitri | ⊢ ( ( 𝑧  ∈  𝑋  ∧  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈 )  ↔  ( 𝑧  Fn  𝐴  ∧  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) ) | 
						
							| 31 |  | simprl | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) | 
						
							| 32 |  | fveq2 | ⊢ ( 𝑘  =  𝐼  →  ( 𝑧 ‘ 𝑘 )  =  ( 𝑧 ‘ 𝐼 ) ) | 
						
							| 33 |  | iftrue | ⊢ ( 𝑘  =  𝐼  →  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  =  𝑈 ) | 
						
							| 34 | 32 33 | eleq12d | ⊢ ( 𝑘  =  𝐼  →  ( ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ↔  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 35 | 31 34 | syl5ibrcom | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝑘  =  𝐼  →  ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 36 |  | simprr | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 37 |  | iffalse | ⊢ ( ¬  𝑘  =  𝐼  →  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  =  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 38 | 37 | eleq2d | ⊢ ( ¬  𝑘  =  𝐼  →  ( ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ↔  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 39 | 36 38 | syl5ibrcom | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ¬  𝑘  =  𝐼  →  ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 40 | 35 39 | pm2.61d | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 41 | 40 | expr | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  →  ( ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  →  ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 42 | 41 | ralimdv | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  →  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 43 | 42 | expimpd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( ( 𝑧 ‘ 𝐼 )  ∈  𝑈  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 44 | 43 | ancomsd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  →  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 45 |  | elssuni | ⊢ ( 𝑈  ∈  ( 𝐹 ‘ 𝐼 )  →  𝑈  ⊆  ∪  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 46 | 45 | ad2antll | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  𝑈  ⊆  ∪  ( 𝐹 ‘ 𝐼 ) ) | 
						
							| 47 | 33 4 | sseq12d | ⊢ ( 𝑘  =  𝐼  →  ( if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ⊆  ∪  ( 𝐹 ‘ 𝑘 )  ↔  𝑈  ⊆  ∪  ( 𝐹 ‘ 𝐼 ) ) ) | 
						
							| 48 | 46 47 | syl5ibrcom | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( 𝑘  =  𝐼  →  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ⊆  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 49 |  | ssid | ⊢ ∪  ( 𝐹 ‘ 𝑘 )  ⊆  ∪  ( 𝐹 ‘ 𝑘 ) | 
						
							| 50 | 37 49 | eqsstrdi | ⊢ ( ¬  𝑘  =  𝐼  →  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ⊆  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 51 | 48 50 | pm2.61d1 | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ⊆  ∪  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 52 | 51 | sseld | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 53 | 52 | ralimdv | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 54 | 34 | rspcv | ⊢ ( 𝐼  ∈  𝐴  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 55 | 54 | ad2antrl | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) | 
						
							| 56 | 53 55 | jcad | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  →  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) ) ) | 
						
							| 57 | 44 56 | impbid | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 )  ↔  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 58 | 57 | anbi2d | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( 𝑧  Fn  𝐴  ∧  ( ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  ∪  ( 𝐹 ‘ 𝑘 )  ∧  ( 𝑧 ‘ 𝐼 )  ∈  𝑈 ) )  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) ) | 
						
							| 59 | 30 58 | bitrid | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ( 𝑧  ∈  𝑋  ∧  ( ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) ) ‘ 𝑧 )  ∈  𝑈 )  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) ) | 
						
							| 60 | 16 59 | bitrd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( 𝑧  ∈  ( ◡ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  “  𝑈 )  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) ) | 
						
							| 61 | 24 | elixp | ⊢ ( 𝑧  ∈  X 𝑘  ∈  𝐴 if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) )  ↔  ( 𝑧  Fn  𝐴  ∧  ∀ 𝑘  ∈  𝐴 ( 𝑧 ‘ 𝑘 )  ∈  if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 62 | 60 61 | bitr4di | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( 𝑧  ∈  ( ◡ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  “  𝑈 )  ↔  𝑧  ∈  X 𝑘  ∈  𝐴 if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 63 | 62 | eqrdv | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐹 : 𝐴 ⟶ Top )  ∧  ( 𝐼  ∈  𝐴  ∧  𝑈  ∈  ( 𝐹 ‘ 𝐼 ) ) )  →  ( ◡ ( 𝑤  ∈  𝑋  ↦  ( 𝑤 ‘ 𝐼 ) )  “  𝑈 )  =  X 𝑘  ∈  𝐴 if ( 𝑘  =  𝐼 ,  𝑈 ,  ∪  ( 𝐹 ‘ 𝑘 ) ) ) |