Metamath Proof Explorer


Definition df-trkgc

Description: Define the class of geometries fulfilling the congruence axioms of reflexivity, identity and transitivity. These are axioms A1 to A3 of Schwabhauser p. 10. With our distance based notation for congruence, transitivity of congruence boils down to transitivity of equality and is already given by eqtr , so it is not listed in this definition. (Contributed by Thierry Arnoux, 24-Aug-2017)

Ref Expression
Assertion df-trkgc 𝒢TarskiC=f|[˙Basef/p]˙[˙distf/d]˙xpypxdy=ydxxpypzpxdy=zdzx=y

Detailed syntax breakdown

Step Hyp Ref Expression
0 cstrkgc class𝒢TarskiC
1 vf setvarf
2 cbs classBase
3 1 cv setvarf
4 3 2 cfv classBasef
5 vp setvarp
6 cds classdist
7 3 6 cfv classdistf
8 vd setvard
9 vx setvarx
10 5 cv setvarp
11 vy setvary
12 9 cv setvarx
13 8 cv setvard
14 11 cv setvary
15 12 14 13 co classxdy
16 14 12 13 co classydx
17 15 16 wceq wffxdy=ydx
18 17 11 10 wral wffypxdy=ydx
19 18 9 10 wral wffxpypxdy=ydx
20 vz setvarz
21 20 cv setvarz
22 21 21 13 co classzdz
23 15 22 wceq wffxdy=zdz
24 12 14 wceq wffx=y
25 23 24 wi wffxdy=zdzx=y
26 25 20 10 wral wffzpxdy=zdzx=y
27 26 11 10 wral wffypzpxdy=zdzx=y
28 27 9 10 wral wffxpypzpxdy=zdzx=y
29 19 28 wa wffxpypxdy=ydxxpypzpxdy=zdzx=y
30 29 8 7 wsbc wff[˙distf/d]˙xpypxdy=ydxxpypzpxdy=zdzx=y
31 30 5 4 wsbc wff[˙Basef/p]˙[˙distf/d]˙xpypxdy=ydxxpypzpxdy=zdzx=y
32 31 1 cab classf|[˙Basef/p]˙[˙distf/d]˙xpypxdy=ydxxpypzpxdy=zdzx=y
33 0 32 wceq wff𝒢TarskiC=f|[˙Basef/p]˙[˙distf/d]˙xpypxdy=ydxxpypzpxdy=zdzx=y