Metamath Proof Explorer


Theorem setsmsds

Description: The distance function of a constructed metric space. (Contributed by Mario Carneiro, 28-Aug-2015)

Ref Expression
Hypotheses setsms.x
|- ( ph -> X = ( Base ` M ) )
setsms.d
|- ( ph -> D = ( ( dist ` M ) |` ( X X. X ) ) )
setsms.k
|- ( ph -> K = ( M sSet <. ( TopSet ` ndx ) , ( MetOpen ` D ) >. ) )
Assertion setsmsds
|- ( ph -> ( dist ` M ) = ( dist ` K ) )

Proof

Step Hyp Ref Expression
1 setsms.x
 |-  ( ph -> X = ( Base ` M ) )
2 setsms.d
 |-  ( ph -> D = ( ( dist ` M ) |` ( X X. X ) ) )
3 setsms.k
 |-  ( ph -> K = ( M sSet <. ( TopSet ` ndx ) , ( MetOpen ` D ) >. ) )
4 dsid
 |-  dist = Slot ( dist ` ndx )
5 9re
 |-  9 e. RR
6 1nn
 |-  1 e. NN
7 2nn0
 |-  2 e. NN0
8 9nn0
 |-  9 e. NN0
9 9lt10
 |-  9 < ; 1 0
10 6 7 8 9 declti
 |-  9 < ; 1 2
11 5 10 gtneii
 |-  ; 1 2 =/= 9
12 dsndx
 |-  ( dist ` ndx ) = ; 1 2
13 tsetndx
 |-  ( TopSet ` ndx ) = 9
14 12 13 neeq12i
 |-  ( ( dist ` ndx ) =/= ( TopSet ` ndx ) <-> ; 1 2 =/= 9 )
15 11 14 mpbir
 |-  ( dist ` ndx ) =/= ( TopSet ` ndx )
16 4 15 setsnid
 |-  ( dist ` M ) = ( dist ` ( M sSet <. ( TopSet ` ndx ) , ( MetOpen ` D ) >. ) )
17 3 fveq2d
 |-  ( ph -> ( dist ` K ) = ( dist ` ( M sSet <. ( TopSet ` ndx ) , ( MetOpen ` D ) >. ) ) )
18 16 17 eqtr4id
 |-  ( ph -> ( dist ` M ) = ( dist ` K ) )