This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Two ways to express an extended metric on an unspecified base. (Contributed by Mario Carneiro, 13-Oct-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xmetunirn | |- ( D e. U. ran *Met <-> D e. ( *Met ` dom dom D ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ovex | |- ( RR* ^m ( x X. x ) ) e. _V |
|
| 2 | 1 | rabex | |- { d e. ( RR* ^m ( x X. x ) ) | A. y e. x A. z e. x ( ( ( y d z ) = 0 <-> y = z ) /\ A. w e. x ( y d z ) <_ ( ( w d y ) +e ( w d z ) ) ) } e. _V |
| 3 | df-xmet | |- *Met = ( x e. _V |-> { d e. ( RR* ^m ( x X. x ) ) | A. y e. x A. z e. x ( ( ( y d z ) = 0 <-> y = z ) /\ A. w e. x ( y d z ) <_ ( ( w d y ) +e ( w d z ) ) ) } ) |
|
| 4 | 2 3 | fnmpti | |- *Met Fn _V |
| 5 | fnunirn | |- ( *Met Fn _V -> ( D e. U. ran *Met <-> E. x e. _V D e. ( *Met ` x ) ) ) |
|
| 6 | 4 5 | ax-mp | |- ( D e. U. ran *Met <-> E. x e. _V D e. ( *Met ` x ) ) |
| 7 | id | |- ( D e. ( *Met ` x ) -> D e. ( *Met ` x ) ) |
|
| 8 | xmetdmdm | |- ( D e. ( *Met ` x ) -> x = dom dom D ) |
|
| 9 | 8 | fveq2d | |- ( D e. ( *Met ` x ) -> ( *Met ` x ) = ( *Met ` dom dom D ) ) |
| 10 | 7 9 | eleqtrd | |- ( D e. ( *Met ` x ) -> D e. ( *Met ` dom dom D ) ) |
| 11 | 10 | rexlimivw | |- ( E. x e. _V D e. ( *Met ` x ) -> D e. ( *Met ` dom dom D ) ) |
| 12 | 6 11 | sylbi | |- ( D e. U. ran *Met -> D e. ( *Met ` dom dom D ) ) |
| 13 | fvssunirn | |- ( *Met ` dom dom D ) C_ U. ran *Met |
|
| 14 | 13 | sseli | |- ( D e. ( *Met ` dom dom D ) -> D e. U. ran *Met ) |
| 15 | 12 14 | impbii | |- ( D e. U. ran *Met <-> D e. ( *Met ` dom dom D ) ) |