| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tgbtwnconn.p |  |-  P = ( Base ` G ) | 
						
							| 2 |  | tgbtwnconn.i |  |-  I = ( Itv ` G ) | 
						
							| 3 |  | tgbtwnconn.g |  |-  ( ph -> G e. TarskiG ) | 
						
							| 4 |  | tgbtwnconn.a |  |-  ( ph -> A e. P ) | 
						
							| 5 |  | tgbtwnconn.b |  |-  ( ph -> B e. P ) | 
						
							| 6 |  | tgbtwnconn.c |  |-  ( ph -> C e. P ) | 
						
							| 7 |  | tgbtwnconn.d |  |-  ( ph -> D e. P ) | 
						
							| 8 |  | tgbtwnconnln1.l |  |-  L = ( LineG ` G ) | 
						
							| 9 |  | tgbtwnconnln1.1 |  |-  ( ph -> A =/= B ) | 
						
							| 10 |  | tgbtwnconnln1.2 |  |-  ( ph -> B e. ( A I C ) ) | 
						
							| 11 |  | tgbtwnconnln1.3 |  |-  ( ph -> B e. ( A I D ) ) | 
						
							| 12 | 3 | adantr |  |-  ( ( ph /\ C e. ( A I D ) ) -> G e. TarskiG ) | 
						
							| 13 | 6 | adantr |  |-  ( ( ph /\ C e. ( A I D ) ) -> C e. P ) | 
						
							| 14 | 7 | adantr |  |-  ( ( ph /\ C e. ( A I D ) ) -> D e. P ) | 
						
							| 15 | 4 | adantr |  |-  ( ( ph /\ C e. ( A I D ) ) -> A e. P ) | 
						
							| 16 |  | simpr |  |-  ( ( ph /\ C e. ( A I D ) ) -> C e. ( A I D ) ) | 
						
							| 17 | 1 8 2 12 13 14 15 16 | btwncolg2 |  |-  ( ( ph /\ C e. ( A I D ) ) -> ( A e. ( C L D ) \/ C = D ) ) | 
						
							| 18 | 3 | adantr |  |-  ( ( ph /\ D e. ( A I C ) ) -> G e. TarskiG ) | 
						
							| 19 | 6 | adantr |  |-  ( ( ph /\ D e. ( A I C ) ) -> C e. P ) | 
						
							| 20 | 7 | adantr |  |-  ( ( ph /\ D e. ( A I C ) ) -> D e. P ) | 
						
							| 21 | 4 | adantr |  |-  ( ( ph /\ D e. ( A I C ) ) -> A e. P ) | 
						
							| 22 |  | eqid |  |-  ( dist ` G ) = ( dist ` G ) | 
						
							| 23 |  | simpr |  |-  ( ( ph /\ D e. ( A I C ) ) -> D e. ( A I C ) ) | 
						
							| 24 | 1 22 2 18 21 20 19 23 | tgbtwncom |  |-  ( ( ph /\ D e. ( A I C ) ) -> D e. ( C I A ) ) | 
						
							| 25 | 1 8 2 18 19 20 21 24 | btwncolg3 |  |-  ( ( ph /\ D e. ( A I C ) ) -> ( A e. ( C L D ) \/ C = D ) ) | 
						
							| 26 | 1 2 3 4 5 6 7 9 10 11 | tgbtwnconn1 |  |-  ( ph -> ( C e. ( A I D ) \/ D e. ( A I C ) ) ) | 
						
							| 27 | 17 25 26 | mpjaodan |  |-  ( ph -> ( A e. ( C L D ) \/ C = D ) ) |