Metamath Proof Explorer


Theorem hlbtwn

Description: Betweenness is a sufficient condition to swap half-lines. (Contributed by Thierry Arnoux, 21-Feb-2020)

Ref Expression
Hypotheses ishlg.p
|- P = ( Base ` G )
ishlg.i
|- I = ( Itv ` G )
ishlg.k
|- K = ( hlG ` G )
ishlg.a
|- ( ph -> A e. P )
ishlg.b
|- ( ph -> B e. P )
ishlg.c
|- ( ph -> C e. P )
hlln.1
|- ( ph -> G e. TarskiG )
hltr.d
|- ( ph -> D e. P )
hlbtwn.1
|- ( ph -> D e. ( C I B ) )
hlbtwn.2
|- ( ph -> B =/= C )
hlbtwn.3
|- ( ph -> D =/= C )
Assertion hlbtwn
|- ( ph -> ( A ( K ` C ) B <-> A ( K ` C ) D ) )

Proof

Step Hyp Ref Expression
1 ishlg.p
 |-  P = ( Base ` G )
2 ishlg.i
 |-  I = ( Itv ` G )
3 ishlg.k
 |-  K = ( hlG ` G )
4 ishlg.a
 |-  ( ph -> A e. P )
5 ishlg.b
 |-  ( ph -> B e. P )
6 ishlg.c
 |-  ( ph -> C e. P )
7 hlln.1
 |-  ( ph -> G e. TarskiG )
8 hltr.d
 |-  ( ph -> D e. P )
9 hlbtwn.1
 |-  ( ph -> D e. ( C I B ) )
10 hlbtwn.2
 |-  ( ph -> B =/= C )
11 hlbtwn.3
 |-  ( ph -> D =/= C )
12 10 11 2thd
 |-  ( ph -> ( B =/= C <-> D =/= C ) )
13 7 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> G e. TarskiG )
14 6 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> C e. P )
15 4 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> A e. P )
16 8 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> D e. P )
17 5 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> B e. P )
18 simpr
 |-  ( ( ph /\ A e. ( C I B ) ) -> A e. ( C I B ) )
19 9 adantr
 |-  ( ( ph /\ A e. ( C I B ) ) -> D e. ( C I B ) )
20 1 2 13 14 15 16 17 18 19 tgbtwnconn3
 |-  ( ( ph /\ A e. ( C I B ) ) -> ( A e. ( C I D ) \/ D e. ( C I A ) ) )
21 eqid
 |-  ( dist ` G ) = ( dist ` G )
22 7 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> G e. TarskiG )
23 6 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> C e. P )
24 8 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> D e. P )
25 5 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> B e. P )
26 4 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> A e. P )
27 9 adantr
 |-  ( ( ph /\ B e. ( C I A ) ) -> D e. ( C I B ) )
28 simpr
 |-  ( ( ph /\ B e. ( C I A ) ) -> B e. ( C I A ) )
29 1 21 2 22 23 24 25 26 27 28 tgbtwnexch
 |-  ( ( ph /\ B e. ( C I A ) ) -> D e. ( C I A ) )
30 29 olcd
 |-  ( ( ph /\ B e. ( C I A ) ) -> ( A e. ( C I D ) \/ D e. ( C I A ) ) )
31 20 30 jaodan
 |-  ( ( ph /\ ( A e. ( C I B ) \/ B e. ( C I A ) ) ) -> ( A e. ( C I D ) \/ D e. ( C I A ) ) )
32 7 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> G e. TarskiG )
33 6 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> C e. P )
34 4 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> A e. P )
35 8 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> D e. P )
36 5 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> B e. P )
37 simpr
 |-  ( ( ph /\ A e. ( C I D ) ) -> A e. ( C I D ) )
38 9 adantr
 |-  ( ( ph /\ A e. ( C I D ) ) -> D e. ( C I B ) )
39 1 21 2 32 33 34 35 36 37 38 tgbtwnexch
 |-  ( ( ph /\ A e. ( C I D ) ) -> A e. ( C I B ) )
40 39 orcd
 |-  ( ( ph /\ A e. ( C I D ) ) -> ( A e. ( C I B ) \/ B e. ( C I A ) ) )
41 7 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> G e. TarskiG )
42 6 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> C e. P )
43 8 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> D e. P )
44 4 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> A e. P )
45 5 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> B e. P )
46 11 necomd
 |-  ( ph -> C =/= D )
47 46 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> C =/= D )
48 simpr
 |-  ( ( ph /\ D e. ( C I A ) ) -> D e. ( C I A ) )
49 9 adantr
 |-  ( ( ph /\ D e. ( C I A ) ) -> D e. ( C I B ) )
50 1 2 41 42 43 44 45 47 48 49 tgbtwnconn1
 |-  ( ( ph /\ D e. ( C I A ) ) -> ( A e. ( C I B ) \/ B e. ( C I A ) ) )
51 40 50 jaodan
 |-  ( ( ph /\ ( A e. ( C I D ) \/ D e. ( C I A ) ) ) -> ( A e. ( C I B ) \/ B e. ( C I A ) ) )
52 31 51 impbida
 |-  ( ph -> ( ( A e. ( C I B ) \/ B e. ( C I A ) ) <-> ( A e. ( C I D ) \/ D e. ( C I A ) ) ) )
53 12 52 3anbi23d
 |-  ( ph -> ( ( A =/= C /\ B =/= C /\ ( A e. ( C I B ) \/ B e. ( C I A ) ) ) <-> ( A =/= C /\ D =/= C /\ ( A e. ( C I D ) \/ D e. ( C I A ) ) ) ) )
54 1 2 3 4 5 6 7 ishlg
 |-  ( ph -> ( A ( K ` C ) B <-> ( A =/= C /\ B =/= C /\ ( A e. ( C I B ) \/ B e. ( C I A ) ) ) ) )
55 1 2 3 4 8 6 7 ishlg
 |-  ( ph -> ( A ( K ` C ) D <-> ( A =/= C /\ D =/= C /\ ( A e. ( C I D ) \/ D e. ( C I A ) ) ) ) )
56 53 54 55 3bitr4d
 |-  ( ph -> ( A ( K ` C ) B <-> A ( K ` C ) D ) )