Metamath Proof Explorer


Theorem eengstr

Description: The Euclidean geometry as a structure. (Contributed by Thierry Arnoux, 15-Mar-2019)

Ref Expression
Assertion eengstr N𝔼𝒢NStruct117

Proof

Step Hyp Ref Expression
1 eengv N𝔼𝒢N=Basendx𝔼Ndistndxx𝔼N,y𝔼Ni=1Nxiyi2Itvndxx𝔼N,y𝔼Nz𝔼N|zBtwnxyLine𝒢ndxx𝔼N,y𝔼Nxz𝔼N|zBtwnxyxBtwnzyyBtwnxz
2 1nn 1
3 basendx Basendx=1
4 2nn0 20
5 1nn0 10
6 1lt10 1<10
7 2 4 5 6 declti 1<12
8 2nn 2
9 5 8 decnncl 12
10 dsndx distndx=12
11 2 3 7 9 10 strle2 Basendx𝔼Ndistndxx𝔼N,y𝔼Ni=1Nxiyi2Struct112
12 6nn 6
13 5 12 decnncl 16
14 itvndx Itvndx=16
15 6nn0 60
16 7nn 7
17 6lt7 6<7
18 5 15 16 17 declt 16<17
19 5 16 decnncl 17
20 lngndx Line𝒢ndx=17
21 13 14 18 19 20 strle2 Itvndxx𝔼N,y𝔼Nz𝔼N|zBtwnxyLine𝒢ndxx𝔼N,y𝔼Nxz𝔼N|zBtwnxyxBtwnzyyBtwnxzStruct1617
22 2lt6 2<6
23 5 4 12 22 declt 12<16
24 11 21 23 strleun Basendx𝔼Ndistndxx𝔼N,y𝔼Ni=1Nxiyi2Itvndxx𝔼N,y𝔼Nz𝔼N|zBtwnxyLine𝒢ndxx𝔼N,y𝔼Nxz𝔼N|zBtwnxyxBtwnzyyBtwnxzStruct117
25 1 24 eqbrtrdi N𝔼𝒢NStruct117