Metamath Proof Explorer


Theorem axlowdim2

Description: The lower two-dimensional axiom. In any space where the dimension is greater than one, there are three non-colinear points. Axiom A8 of Schwabhauser p. 12. (Contributed by Scott Fenton, 15-Apr-2013)

Ref Expression
Assertion axlowdim2 N2x𝔼Ny𝔼Nz𝔼N¬xBtwnyzyBtwnzxzBtwnxy

Proof

Step Hyp Ref Expression
1 0re 0
2 1 1 axlowdimlem5 N210203N×0𝔼N
3 1re 1
4 3 1 axlowdimlem5 N211203N×0𝔼N
5 1 3 axlowdimlem5 N210213N×0𝔼N
6 eqid 10203N×0=10203N×0
7 eqid 11203N×0=11203N×0
8 eqid 10213N×0=10213N×0
9 6 7 8 axlowdimlem6 N2¬10203N×0Btwn11203N×010213N×011203N×0Btwn10213N×010203N×010213N×0Btwn10203N×011203N×0
10 opeq2 z=10213N×011203N×0z=11203N×010213N×0
11 10 breq2d z=10213N×010203N×0Btwn11203N×0z10203N×0Btwn11203N×010213N×0
12 opeq1 z=10213N×0z10203N×0=10213N×010203N×0
13 12 breq2d z=10213N×011203N×0Btwnz10203N×011203N×0Btwn10213N×010203N×0
14 breq1 z=10213N×0zBtwn10203N×011203N×010213N×0Btwn10203N×011203N×0
15 11 13 14 3orbi123d z=10213N×010203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×010203N×0Btwn11203N×010213N×011203N×0Btwn10213N×010203N×010213N×0Btwn10203N×011203N×0
16 15 notbid z=10213N×0¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0¬10203N×0Btwn11203N×010213N×011203N×0Btwn10213N×010203N×010213N×0Btwn10203N×011203N×0
17 16 rspcev 10213N×0𝔼N¬10203N×0Btwn11203N×010213N×011203N×0Btwn10213N×010203N×010213N×0Btwn10203N×011203N×0z𝔼N¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0
18 5 9 17 syl2anc N2z𝔼N¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0
19 breq1 x=10203N×0xBtwnyz10203N×0Btwnyz
20 opeq2 x=10203N×0zx=z10203N×0
21 20 breq2d x=10203N×0yBtwnzxyBtwnz10203N×0
22 opeq1 x=10203N×0xy=10203N×0y
23 22 breq2d x=10203N×0zBtwnxyzBtwn10203N×0y
24 19 21 23 3orbi123d x=10203N×0xBtwnyzyBtwnzxzBtwnxy10203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0y
25 24 notbid x=10203N×0¬xBtwnyzyBtwnzxzBtwnxy¬10203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0y
26 25 rexbidv x=10203N×0z𝔼N¬xBtwnyzyBtwnzxzBtwnxyz𝔼N¬10203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0y
27 opeq1 y=11203N×0yz=11203N×0z
28 27 breq2d y=11203N×010203N×0Btwnyz10203N×0Btwn11203N×0z
29 breq1 y=11203N×0yBtwnz10203N×011203N×0Btwnz10203N×0
30 opeq2 y=11203N×010203N×0y=10203N×011203N×0
31 30 breq2d y=11203N×0zBtwn10203N×0yzBtwn10203N×011203N×0
32 28 29 31 3orbi123d y=11203N×010203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0y10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0
33 32 notbid y=11203N×0¬10203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0y¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0
34 33 rexbidv y=11203N×0z𝔼N¬10203N×0BtwnyzyBtwnz10203N×0zBtwn10203N×0yz𝔼N¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0
35 26 34 rspc2ev 10203N×0𝔼N11203N×0𝔼Nz𝔼N¬10203N×0Btwn11203N×0z11203N×0Btwnz10203N×0zBtwn10203N×011203N×0x𝔼Ny𝔼Nz𝔼N¬xBtwnyzyBtwnzxzBtwnxy
36 2 4 18 35 syl3anc N2x𝔼Ny𝔼Nz𝔼N¬xBtwnyzyBtwnzxzBtwnxy