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 ) } ) |