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 φ X = Base M
setsms.d φ D = dist M X × X
setsms.k φ K = M sSet TopSet ndx MetOpen D
Assertion setsmsds φ dist M = dist K

Proof

Step Hyp Ref Expression
1 setsms.x φ X = Base M
2 setsms.d φ D = dist M X × X
3 setsms.k φ K = M sSet TopSet ndx MetOpen D
4 dsid dist = Slot dist ndx
5 9re 9
6 1nn 1
7 2nn0 2 0
8 9nn0 9 0
9 9lt10 9 < 10
10 6 7 8 9 declti 9 < 12
11 5 10 gtneii 12 9
12 dsndx dist ndx = 12
13 tsetndx TopSet ndx = 9
14 12 13 neeq12i dist ndx TopSet ndx 12 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 φ dist K = dist M sSet TopSet ndx MetOpen D
18 16 17 eqtr4id φ dist M = dist K