Metamath Proof Explorer


Theorem ttgds

Description: The metric of a subcomplex Hilbert space augmented with betweenness. (Contributed by Thierry Arnoux, 25-Mar-2019) (Revised by AV, 29-Oct-2024)

Ref Expression
Hypotheses ttgval.n G = to𝒢 Tarski H
ttgds.1 D = dist H
Assertion ttgds D = dist G

Proof

Step Hyp Ref Expression
1 ttgval.n G = to𝒢 Tarski H
2 ttgds.1 D = dist H
3 dsid dist = Slot dist ndx
4 slotslnbpsd Line 𝒢 ndx Base ndx Line 𝒢 ndx + ndx Line 𝒢 ndx ndx Line 𝒢 ndx dist ndx
5 simprr Line 𝒢 ndx Base ndx Line 𝒢 ndx + ndx Line 𝒢 ndx ndx Line 𝒢 ndx dist ndx Line 𝒢 ndx dist ndx
6 4 5 ax-mp Line 𝒢 ndx dist ndx
7 6 necomi dist ndx Line 𝒢 ndx
8 slotsinbpsd Itv ndx Base ndx Itv ndx + ndx Itv ndx ndx Itv ndx dist ndx
9 simprr Itv ndx Base ndx Itv ndx + ndx Itv ndx ndx Itv ndx dist ndx Itv ndx dist ndx
10 8 9 ax-mp Itv ndx dist ndx
11 10 necomi dist ndx Itv ndx
12 1 3 7 11 ttglem dist H = dist G
13 2 12 eqtri D = dist G