Metamath Proof Explorer


Theorem doch11

Description: Orthocomplement is one-to-one. (Contributed by NM, 12-Aug-2014)

Ref Expression
Hypotheses doch11.h H=LHypK
doch11.i I=DIsoHKW
doch11.o ˙=ocHKW
doch11.k φKHLWH
doch11.x φXranI
doch11.y φYranI
Assertion doch11 φ˙X=˙YX=Y

Proof

Step Hyp Ref Expression
1 doch11.h H=LHypK
2 doch11.i I=DIsoHKW
3 doch11.o ˙=ocHKW
4 doch11.k φKHLWH
5 doch11.x φXranI
6 doch11.y φYranI
7 1 2 3 4 6 5 dochord φYX˙X˙Y
8 1 2 3 4 5 6 dochord φXY˙Y˙X
9 7 8 anbi12d φYXXY˙X˙Y˙Y˙X
10 eqcom X=YY=X
11 eqss Y=XYXXY
12 10 11 bitri X=YYXXY
13 eqss ˙X=˙Y˙X˙Y˙Y˙X
14 9 12 13 3bitr4g φX=Y˙X=˙Y
15 14 bicomd φ˙X=˙YX=Y