Description: Define the quotient topology given a function f and topology j on the domain of f . (Contributed by Mario Carneiro, 23-Mar-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-qtop | |- qTop = ( j e. _V , f e. _V |-> { s e. ~P ( f " U. j ) | ( ( `' f " s ) i^i U. j ) e. j } ) | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | cqtop | |- qTop  | 
						|
| 1 | vj | |- j  | 
						|
| 2 | cvv | |- _V  | 
						|
| 3 | vf | |- f  | 
						|
| 4 | vs | |- s  | 
						|
| 5 | 3 | cv | |- f  | 
						
| 6 | 1 | cv | |- j  | 
						
| 7 | 6 | cuni | |- U. j  | 
						
| 8 | 5 7 | cima | |- ( f " U. j )  | 
						
| 9 | 8 | cpw | |- ~P ( f " U. j )  | 
						
| 10 | 5 | ccnv | |- `' f  | 
						
| 11 | 4 | cv | |- s  | 
						
| 12 | 10 11 | cima | |- ( `' f " s )  | 
						
| 13 | 12 7 | cin | |- ( ( `' f " s ) i^i U. j )  | 
						
| 14 | 13 6 | wcel | |- ( ( `' f " s ) i^i U. j ) e. j  | 
						
| 15 | 14 4 9 | crab |  |-  { s e. ~P ( f " U. j ) | ( ( `' f " s ) i^i U. j ) e. j } | 
						
| 16 | 1 3 2 2 15 | cmpo |  |-  ( j e. _V , f e. _V |-> { s e. ~P ( f " U. j ) | ( ( `' f " s ) i^i U. j ) e. j } ) | 
						
| 17 | 0 16 | wceq |  |-  qTop = ( j e. _V , f e. _V |-> { s e. ~P ( f " U. j ) | ( ( `' f " s ) i^i U. j ) e. j } ) |