| 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 ) ) |