| Step | Hyp | Ref | Expression | 
						
							| 1 |  | topontop | ⊢ ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  →  𝐽  ∈  Top ) | 
						
							| 2 |  | fvssunirn | ⊢ ( Fil ‘ 𝑌 )  ⊆  ∪  ran  Fil | 
						
							| 3 | 2 | sseli | ⊢ ( 𝐿  ∈  ( Fil ‘ 𝑌 )  →  𝐿  ∈  ∪  ran  Fil ) | 
						
							| 4 |  | unieq | ⊢ ( 𝑥  =  𝐽  →  ∪  𝑥  =  ∪  𝐽 ) | 
						
							| 5 |  | unieq | ⊢ ( 𝑦  =  𝐿  →  ∪  𝑦  =  ∪  𝐿 ) | 
						
							| 6 | 4 5 | oveqan12d | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ( ∪  𝑥  ↑m  ∪  𝑦 )  =  ( ∪  𝐽  ↑m  ∪  𝐿 ) ) | 
						
							| 7 |  | simpl | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  𝑥  =  𝐽 ) | 
						
							| 8 | 4 | adantr | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ∪  𝑥  =  ∪  𝐽 ) | 
						
							| 9 | 8 | oveq1d | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ( ∪  𝑥  FilMap  𝑓 )  =  ( ∪  𝐽  FilMap  𝑓 ) ) | 
						
							| 10 |  | simpr | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  𝑦  =  𝐿 ) | 
						
							| 11 | 9 10 | fveq12d | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ( ( ∪  𝑥  FilMap  𝑓 ) ‘ 𝑦 )  =  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) | 
						
							| 12 | 7 11 | oveq12d | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ( 𝑥  fLim  ( ( ∪  𝑥  FilMap  𝑓 ) ‘ 𝑦 ) )  =  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) ) | 
						
							| 13 | 6 12 | mpteq12dv | ⊢ ( ( 𝑥  =  𝐽  ∧  𝑦  =  𝐿 )  →  ( 𝑓  ∈  ( ∪  𝑥  ↑m  ∪  𝑦 )  ↦  ( 𝑥  fLim  ( ( ∪  𝑥  FilMap  𝑓 ) ‘ 𝑦 ) ) )  =  ( 𝑓  ∈  ( ∪  𝐽  ↑m  ∪  𝐿 )  ↦  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) ) ) | 
						
							| 14 |  | df-flf | ⊢  fLimf   =  ( 𝑥  ∈  Top ,  𝑦  ∈  ∪  ran  Fil  ↦  ( 𝑓  ∈  ( ∪  𝑥  ↑m  ∪  𝑦 )  ↦  ( 𝑥  fLim  ( ( ∪  𝑥  FilMap  𝑓 ) ‘ 𝑦 ) ) ) ) | 
						
							| 15 |  | ovex | ⊢ ( ∪  𝐽  ↑m  ∪  𝐿 )  ∈  V | 
						
							| 16 | 15 | mptex | ⊢ ( 𝑓  ∈  ( ∪  𝐽  ↑m  ∪  𝐿 )  ↦  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) )  ∈  V | 
						
							| 17 | 13 14 16 | ovmpoa | ⊢ ( ( 𝐽  ∈  Top  ∧  𝐿  ∈  ∪  ran  Fil )  →  ( 𝐽  fLimf  𝐿 )  =  ( 𝑓  ∈  ( ∪  𝐽  ↑m  ∪  𝐿 )  ↦  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) ) ) | 
						
							| 18 | 1 3 17 | syl2an | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( 𝐽  fLimf  𝐿 )  =  ( 𝑓  ∈  ( ∪  𝐽  ↑m  ∪  𝐿 )  ↦  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) ) ) | 
						
							| 19 |  | toponuni | ⊢ ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  →  𝑋  =  ∪  𝐽 ) | 
						
							| 20 | 19 | eqcomd | ⊢ ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  →  ∪  𝐽  =  𝑋 ) | 
						
							| 21 |  | filunibas | ⊢ ( 𝐿  ∈  ( Fil ‘ 𝑌 )  →  ∪  𝐿  =  𝑌 ) | 
						
							| 22 | 20 21 | oveqan12d | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( ∪  𝐽  ↑m  ∪  𝐿 )  =  ( 𝑋  ↑m  𝑌 ) ) | 
						
							| 23 | 20 | adantr | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ∪  𝐽  =  𝑋 ) | 
						
							| 24 | 23 | oveq1d | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( ∪  𝐽  FilMap  𝑓 )  =  ( 𝑋  FilMap  𝑓 ) ) | 
						
							| 25 | 24 | fveq1d | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 )  =  ( ( 𝑋  FilMap  𝑓 ) ‘ 𝐿 ) ) | 
						
							| 26 | 25 | oveq2d | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) )  =  ( 𝐽  fLim  ( ( 𝑋  FilMap  𝑓 ) ‘ 𝐿 ) ) ) | 
						
							| 27 | 22 26 | mpteq12dv | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( 𝑓  ∈  ( ∪  𝐽  ↑m  ∪  𝐿 )  ↦  ( 𝐽  fLim  ( ( ∪  𝐽  FilMap  𝑓 ) ‘ 𝐿 ) ) )  =  ( 𝑓  ∈  ( 𝑋  ↑m  𝑌 )  ↦  ( 𝐽  fLim  ( ( 𝑋  FilMap  𝑓 ) ‘ 𝐿 ) ) ) ) | 
						
							| 28 | 18 27 | eqtrd | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐿  ∈  ( Fil ‘ 𝑌 ) )  →  ( 𝐽  fLimf  𝐿 )  =  ( 𝑓  ∈  ( 𝑋  ↑m  𝑌 )  ↦  ( 𝐽  fLim  ( ( 𝑋  FilMap  𝑓 ) ‘ 𝐿 ) ) ) ) |