Metamath Proof Explorer


Theorem tgcgrcoml

Description: Congruence commutes on the LHS. Variant of Theorem 2.5 of Schwabhauser p. 27, but in a convenient form for a common case. (Contributed by David A. Wheeler, 29-Jun-2020)

Ref Expression
Hypotheses tkgeom.p ⊢ P = Base G
tkgeom.d ⊢ - ˙ = dist ⁡ G
tkgeom.i ⊢ I = Itv ⁡ G
tkgeom.g ⊢ φ → G ∈ 𝒢 Tarski
tgcgrcomr.a ⊢ φ → A ∈ P
tgcgrcomr.b ⊢ φ → B ∈ P
tgcgrcomr.c ⊢ φ → C ∈ P
tgcgrcomr.d ⊢ φ → D ∈ P
tgcgrcomr.6 ⊢ φ → A - ˙ B = C - ˙ D
Assertion tgcgrcoml ⊢ φ → B - ˙ A = C - ˙ D

Proof

Step Hyp Ref Expression
1 tkgeom.p ⊢ P = Base G
2 tkgeom.d ⊢ - ˙ = dist ⁡ G
3 tkgeom.i ⊢ I = Itv ⁡ G
4 tkgeom.g ⊢ φ → G ∈ 𝒢 Tarski
5 tgcgrcomr.a ⊢ φ → A ∈ P
6 tgcgrcomr.b ⊢ φ → B ∈ P
7 tgcgrcomr.c ⊢ φ → C ∈ P
8 tgcgrcomr.d ⊢ φ → D ∈ P
9 tgcgrcomr.6 ⊢ φ → A - ˙ B = C - ˙ D
10 1 2 3 4 5 6 axtgcgrrflx ⊢ φ → A - ˙ B = B - ˙ A
11 10 9 eqtr3d ⊢ φ → B - ˙ A = C - ˙ D