Metamath Proof Explorer


Theorem cgr3simp2

Description: Deduce segment congruence from a triangle congruence. This is a portion of CPCTC, focusing on a specific segment. (Contributed by Thierry Arnoux, 27-Apr-2019)

Ref Expression
Hypotheses tgcgrxfr.p P=BaseG
tgcgrxfr.m -˙=distG
tgcgrxfr.i I=ItvG
tgcgrxfr.r ˙=𝒢G
tgcgrxfr.g φG𝒢Tarski
tgbtwnxfr.a φAP
tgbtwnxfr.b φBP
tgbtwnxfr.c φCP
tgbtwnxfr.d φDP
tgbtwnxfr.e φEP
tgbtwnxfr.f φFP
tgbtwnxfr.2 φ⟨“ABC”⟩˙⟨“DEF”⟩
Assertion cgr3simp2 φB-˙C=E-˙F

Proof

Step Hyp Ref Expression
1 tgcgrxfr.p P=BaseG
2 tgcgrxfr.m -˙=distG
3 tgcgrxfr.i I=ItvG
4 tgcgrxfr.r ˙=𝒢G
5 tgcgrxfr.g φG𝒢Tarski
6 tgbtwnxfr.a φAP
7 tgbtwnxfr.b φBP
8 tgbtwnxfr.c φCP
9 tgbtwnxfr.d φDP
10 tgbtwnxfr.e φEP
11 tgbtwnxfr.f φFP
12 tgbtwnxfr.2 φ⟨“ABC”⟩˙⟨“DEF”⟩
13 1 2 4 5 6 7 8 9 10 11 trgcgrg φ⟨“ABC”⟩˙⟨“DEF”⟩A-˙B=D-˙EB-˙C=E-˙FC-˙A=F-˙D
14 12 13 mpbid φA-˙B=D-˙EB-˙C=E-˙FC-˙A=F-˙D
15 14 simp2d φB-˙C=E-˙F