Metamath Proof Explorer


Theorem metidval

Description: Value of the metric identification relation. (Contributed by Thierry Arnoux, 7-Feb-2018)

Ref Expression
Assertion metidval DPsMetX~MetD=xy|xXyXxDy=0

Proof

Step Hyp Ref Expression
1 df-metid ~Met=dranPsMetxy|xdomdomdydomdomdxdy=0
2 simpr DPsMetXd=Dd=D
3 2 dmeqd DPsMetXd=Ddomd=domD
4 3 dmeqd DPsMetXd=Ddomdomd=domdomD
5 psmetdmdm DPsMetXX=domdomD
6 5 adantr DPsMetXd=DX=domdomD
7 4 6 eqtr4d DPsMetXd=Ddomdomd=X
8 7 eleq2d DPsMetXd=DxdomdomdxX
9 7 eleq2d DPsMetXd=DydomdomdyX
10 8 9 anbi12d DPsMetXd=DxdomdomdydomdomdxXyX
11 2 oveqd DPsMetXd=Dxdy=xDy
12 11 eqeq1d DPsMetXd=Dxdy=0xDy=0
13 10 12 anbi12d DPsMetXd=Dxdomdomdydomdomdxdy=0xXyXxDy=0
14 13 opabbidv DPsMetXd=Dxy|xdomdomdydomdomdxdy=0=xy|xXyXxDy=0
15 elfvunirn DPsMetXDranPsMet
16 opabssxp xy|xXyXxDy=0X×X
17 elfvex DPsMetXXV
18 17 17 xpexd DPsMetXX×XV
19 ssexg xy|xXyXxDy=0X×XX×XVxy|xXyXxDy=0V
20 16 18 19 sylancr DPsMetXxy|xXyXxDy=0V
21 1 14 15 20 fvmptd2 DPsMetX~MetD=xy|xXyXxDy=0