Description: Define a function shifter. This operation offsets the value argument of a function (ordinarily on a subset of CC ) and produces a new function on CC . See shftval for its value. (Contributed by NM, 20-Jul-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-shft | |- shift = ( f e. _V , x e. CC |-> { <. y , z >. | ( y e. CC /\ ( y - x ) f z ) } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | cshi | |- shift | |
| 1 | vf | |- f | |
| 2 | cvv | |- _V | |
| 3 | vx | |- x | |
| 4 | cc | |- CC | |
| 5 | vy | |- y | |
| 6 | vz | |- z | |
| 7 | 5 | cv | |- y | 
| 8 | 7 4 | wcel | |- y e. CC | 
| 9 | cmin | |- - | |
| 10 | 3 | cv | |- x | 
| 11 | 7 10 9 | co | |- ( y - x ) | 
| 12 | 1 | cv | |- f | 
| 13 | 6 | cv | |- z | 
| 14 | 11 13 12 | wbr | |- ( y - x ) f z | 
| 15 | 8 14 | wa | |- ( y e. CC /\ ( y - x ) f z ) | 
| 16 | 15 5 6 | copab |  |-  { <. y , z >. | ( y e. CC /\ ( y - x ) f z ) } | 
| 17 | 1 3 2 4 16 | cmpo |  |-  ( f e. _V , x e. CC |-> { <. y , z >. | ( y e. CC /\ ( y - x ) f z ) } ) | 
| 18 | 0 17 | wceq |  |-  shift = ( f e. _V , x e. CC |-> { <. y , z >. | ( y e. CC /\ ( y - x ) f z ) } ) |