Metamath Proof Explorer


Theorem tgcgrtriv

Description: Degenerate segments are congruent. Theorem 2.8 of Schwabhauser p. 28. (Contributed by Thierry Arnoux, 23-Mar-2019)

Ref Expression
Hypotheses tkgeom.p
|- P = ( Base ` G )
tkgeom.d
|- .- = ( dist ` G )
tkgeom.i
|- I = ( Itv ` G )
tkgeom.g
|- ( ph -> G e. TarskiG )
tgcgrtriv.1
|- ( ph -> A e. P )
tgcgrtriv.2
|- ( ph -> B e. P )
Assertion tgcgrtriv
|- ( ph -> ( A .- A ) = ( B .- B ) )

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
 |-  ( ph -> G e. TarskiG )
5 tgcgrtriv.1
 |-  ( ph -> A e. P )
6 tgcgrtriv.2
 |-  ( ph -> B e. P )
7 4 ad2antrr
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> G e. TarskiG )
8 5 ad2antrr
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> A e. P )
9 simplr
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> x e. P )
10 6 ad2antrr
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> B e. P )
11 simprr
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> ( A .- x ) = ( B .- B ) )
12 1 2 3 7 8 9 10 11 axtgcgrid
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> A = x )
13 12 oveq2d
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> ( A .- A ) = ( A .- x ) )
14 13 11 eqtrd
 |-  ( ( ( ph /\ x e. P ) /\ ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) ) -> ( A .- A ) = ( B .- B ) )
15 1 2 3 4 6 5 6 6 axtgsegcon
 |-  ( ph -> E. x e. P ( A e. ( B I x ) /\ ( A .- x ) = ( B .- B ) ) )
16 14 15 r19.29a
 |-  ( ph -> ( A .- A ) = ( B .- B ) )