Metamath Proof Explorer


Theorem ragmir

Description: Right angle property is preserved by point inversion. Theorem 8.4 of Schwabhauser p. 58. (Contributed by Thierry Arnoux, 25-Aug-2019)

Ref Expression
Hypotheses israg.p P=BaseG
israg.d -˙=distG
israg.i I=ItvG
israg.l L=Line𝒢G
israg.s S=pInv𝒢G
israg.g φG𝒢Tarski
israg.a φAP
israg.b φBP
israg.c φCP
ragmir.1 φ⟨“ABC”⟩𝒢G
Assertion ragmir φ⟨“ABSBC”⟩𝒢G

Proof

Step Hyp Ref Expression
1 israg.p P=BaseG
2 israg.d -˙=distG
3 israg.i I=ItvG
4 israg.l L=Line𝒢G
5 israg.s S=pInv𝒢G
6 israg.g φG𝒢Tarski
7 israg.a φAP
8 israg.b φBP
9 israg.c φCP
10 ragmir.1 φ⟨“ABC”⟩𝒢G
11 eqid SB=SB
12 1 2 3 4 5 6 8 11 9 mirmir φSBSBC=C
13 12 oveq2d φA-˙SBSBC=A-˙C
14 1 2 3 4 5 6 7 8 9 israg φ⟨“ABC”⟩𝒢GA-˙C=A-˙SBC
15 10 14 mpbid φA-˙C=A-˙SBC
16 13 15 eqtr2d φA-˙SBC=A-˙SBSBC
17 1 2 3 4 5 6 8 11 9 mircl φSBCP
18 1 2 3 4 5 6 7 8 17 israg φ⟨“ABSBC”⟩𝒢GA-˙SBC=A-˙SBSBC
19 16 18 mpbird φ⟨“ABSBC”⟩𝒢G