| Step | Hyp | Ref | Expression | 
						
							| 0 |  | ctsu |  |-  tsums | 
						
							| 1 |  | vw |  |-  w | 
						
							| 2 |  | cvv |  |-  _V | 
						
							| 3 |  | vf |  |-  f | 
						
							| 4 | 3 | cv |  |-  f | 
						
							| 5 | 4 | cdm |  |-  dom f | 
						
							| 6 | 5 | cpw |  |-  ~P dom f | 
						
							| 7 |  | cfn |  |-  Fin | 
						
							| 8 | 6 7 | cin |  |-  ( ~P dom f i^i Fin ) | 
						
							| 9 |  | vs |  |-  s | 
						
							| 10 |  | ctopn |  |-  TopOpen | 
						
							| 11 | 1 | cv |  |-  w | 
						
							| 12 | 11 10 | cfv |  |-  ( TopOpen ` w ) | 
						
							| 13 |  | cflf |  |-  fLimf | 
						
							| 14 | 9 | cv |  |-  s | 
						
							| 15 |  | cfg |  |-  filGen | 
						
							| 16 |  | vz |  |-  z | 
						
							| 17 |  | vy |  |-  y | 
						
							| 18 | 16 | cv |  |-  z | 
						
							| 19 | 17 | cv |  |-  y | 
						
							| 20 | 18 19 | wss |  |-  z C_ y | 
						
							| 21 | 20 17 14 | crab |  |-  { y e. s | z C_ y } | 
						
							| 22 | 16 14 21 | cmpt |  |-  ( z e. s |-> { y e. s | z C_ y } ) | 
						
							| 23 | 22 | crn |  |-  ran ( z e. s |-> { y e. s | z C_ y } ) | 
						
							| 24 | 14 23 15 | co |  |-  ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) | 
						
							| 25 | 12 24 13 | co |  |-  ( ( TopOpen ` w ) fLimf ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) ) | 
						
							| 26 |  | cgsu |  |-  gsum | 
						
							| 27 | 4 19 | cres |  |-  ( f |` y ) | 
						
							| 28 | 11 27 26 | co |  |-  ( w gsum ( f |` y ) ) | 
						
							| 29 | 17 14 28 | cmpt |  |-  ( y e. s |-> ( w gsum ( f |` y ) ) ) | 
						
							| 30 | 29 25 | cfv |  |-  ( ( ( TopOpen ` w ) fLimf ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) ) ` ( y e. s |-> ( w gsum ( f |` y ) ) ) ) | 
						
							| 31 | 9 8 30 | csb |  |-  [_ ( ~P dom f i^i Fin ) / s ]_ ( ( ( TopOpen ` w ) fLimf ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) ) ` ( y e. s |-> ( w gsum ( f |` y ) ) ) ) | 
						
							| 32 | 1 3 2 2 31 | cmpo |  |-  ( w e. _V , f e. _V |-> [_ ( ~P dom f i^i Fin ) / s ]_ ( ( ( TopOpen ` w ) fLimf ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) ) ` ( y e. s |-> ( w gsum ( f |` y ) ) ) ) ) | 
						
							| 33 | 0 32 | wceq |  |-  tsums = ( w e. _V , f e. _V |-> [_ ( ~P dom f i^i Fin ) / s ]_ ( ( ( TopOpen ` w ) fLimf ( s filGen ran ( z e. s |-> { y e. s | z C_ y } ) ) ) ` ( y e. s |-> ( w gsum ( f |` y ) ) ) ) ) |