Description: The transitive closure function. (Contributed by Mario Carneiro, 23-Jun-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | df-tc | |- TC = ( x e. _V |-> |^| { y | ( x C_ y /\ Tr y ) } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | ctc | |- TC |
|
1 | vx | |- x |
|
2 | cvv | |- _V |
|
3 | vy | |- y |
|
4 | 1 | cv | |- x |
5 | 3 | cv | |- y |
6 | 4 5 | wss | |- x C_ y |
7 | 5 | wtr | |- Tr y |
8 | 6 7 | wa | |- ( x C_ y /\ Tr y ) |
9 | 8 3 | cab | |- { y | ( x C_ y /\ Tr y ) } |
10 | 9 | cint | |- |^| { y | ( x C_ y /\ Tr y ) } |
11 | 1 2 10 | cmpt | |- ( x e. _V |-> |^| { y | ( x C_ y /\ Tr y ) } ) |
12 | 0 11 | wceq | |- TC = ( x e. _V |-> |^| { y | ( x C_ y /\ Tr y ) } ) |