Description: Define the full function over F . This is a function with domain _V that always agrees with F for its value. (Contributed by Scott Fenton, 17-Apr-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-fullfun | |- FullFun F = ( Funpart F u. ( ( _V \ dom Funpart F ) X. { (/) } ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | cF | |- F | |
| 1 | 0 | cfullfn | |- FullFun F | 
| 2 | 0 | cfunpart | |- Funpart F | 
| 3 | cvv | |- _V | |
| 4 | 2 | cdm | |- dom Funpart F | 
| 5 | 3 4 | cdif | |- ( _V \ dom Funpart F ) | 
| 6 | c0 | |- (/) | |
| 7 | 6 | csn |  |-  { (/) } | 
| 8 | 5 7 | cxp |  |-  ( ( _V \ dom Funpart F ) X. { (/) } ) | 
| 9 | 2 8 | cun |  |-  ( Funpart F u. ( ( _V \ dom Funpart F ) X. { (/) } ) ) | 
| 10 | 1 9 | wceq |  |-  FullFun F = ( Funpart F u. ( ( _V \ dom Funpart F ) X. { (/) } ) ) |