Metamath Proof Explorer


Theorem metuust

Description: The uniform structure generated by metric D is a uniform structure. (Contributed by Thierry Arnoux, 1-Dec-2017) (Revised by Thierry Arnoux, 11-Feb-2018)

Ref Expression
Assertion metuust
|- ( ( X =/= (/) /\ D e. ( PsMet ` X ) ) -> ( metUnif ` D ) e. ( UnifOn ` X ) )

Proof

Step Hyp Ref Expression
1 metuval
 |-  ( D e. ( PsMet ` X ) -> ( metUnif ` D ) = ( ( X X. X ) filGen ran ( a e. RR+ |-> ( `' D " ( 0 [,) a ) ) ) ) )
2 1 adantl
 |-  ( ( X =/= (/) /\ D e. ( PsMet ` X ) ) -> ( metUnif ` D ) = ( ( X X. X ) filGen ran ( a e. RR+ |-> ( `' D " ( 0 [,) a ) ) ) ) )
3 oveq2
 |-  ( a = b -> ( 0 [,) a ) = ( 0 [,) b ) )
4 3 imaeq2d
 |-  ( a = b -> ( `' D " ( 0 [,) a ) ) = ( `' D " ( 0 [,) b ) ) )
5 4 cbvmptv
 |-  ( a e. RR+ |-> ( `' D " ( 0 [,) a ) ) ) = ( b e. RR+ |-> ( `' D " ( 0 [,) b ) ) )
6 5 rneqi
 |-  ran ( a e. RR+ |-> ( `' D " ( 0 [,) a ) ) ) = ran ( b e. RR+ |-> ( `' D " ( 0 [,) b ) ) )
7 6 metust
 |-  ( ( X =/= (/) /\ D e. ( PsMet ` X ) ) -> ( ( X X. X ) filGen ran ( a e. RR+ |-> ( `' D " ( 0 [,) a ) ) ) ) e. ( UnifOn ` X ) )
8 2 7 eqeltrd
 |-  ( ( X =/= (/) /\ D e. ( PsMet ` X ) ) -> ( metUnif ` D ) e. ( UnifOn ` X ) )