| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							tgbtwnconn.p | 
							⊢ 𝑃  =  ( Base ‘ 𝐺 )  | 
						
						
							| 2 | 
							
								
							 | 
							tgbtwnconn.i | 
							⊢ 𝐼  =  ( Itv ‘ 𝐺 )  | 
						
						
							| 3 | 
							
								
							 | 
							tgbtwnconn.g | 
							⊢ ( 𝜑  →  𝐺  ∈  TarskiG )  | 
						
						
							| 4 | 
							
								
							 | 
							tgbtwnconn.a | 
							⊢ ( 𝜑  →  𝐴  ∈  𝑃 )  | 
						
						
							| 5 | 
							
								
							 | 
							tgbtwnconn.b | 
							⊢ ( 𝜑  →  𝐵  ∈  𝑃 )  | 
						
						
							| 6 | 
							
								
							 | 
							tgbtwnconn.c | 
							⊢ ( 𝜑  →  𝐶  ∈  𝑃 )  | 
						
						
							| 7 | 
							
								
							 | 
							tgbtwnconn.d | 
							⊢ ( 𝜑  →  𝐷  ∈  𝑃 )  | 
						
						
							| 8 | 
							
								
							 | 
							tgbtwnconn2.1 | 
							⊢ ( 𝜑  →  𝐴  ≠  𝐵 )  | 
						
						
							| 9 | 
							
								
							 | 
							tgbtwnconn2.2 | 
							⊢ ( 𝜑  →  𝐵  ∈  ( 𝐴 𝐼 𝐶 ) )  | 
						
						
							| 10 | 
							
								
							 | 
							tgbtwnconn2.3 | 
							⊢ ( 𝜑  →  𝐵  ∈  ( 𝐴 𝐼 𝐷 ) )  | 
						
						
							| 11 | 
							
								
							 | 
							eqid | 
							⊢ ( dist ‘ 𝐺 )  =  ( dist ‘ 𝐺 )  | 
						
						
							| 12 | 
							
								3
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐺  ∈  TarskiG )  | 
						
						
							| 13 | 
							
								4
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐴  ∈  𝑃 )  | 
						
						
							| 14 | 
							
								5
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐵  ∈  𝑃 )  | 
						
						
							| 15 | 
							
								6
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐶  ∈  𝑃 )  | 
						
						
							| 16 | 
							
								7
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐷  ∈  𝑃 )  | 
						
						
							| 17 | 
							
								9
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐵  ∈  ( 𝐴 𝐼 𝐶 ) )  | 
						
						
							| 18 | 
							
								
							 | 
							simpr | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  | 
						
						
							| 19 | 
							
								1 11 2 12 13 14 15 16 17 18
							 | 
							tgbtwnexch3 | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  𝐶  ∈  ( 𝐵 𝐼 𝐷 ) )  | 
						
						
							| 20 | 
							
								19
							 | 
							orcd | 
							⊢ ( ( 𝜑  ∧  𝐶  ∈  ( 𝐴 𝐼 𝐷 ) )  →  ( 𝐶  ∈  ( 𝐵 𝐼 𝐷 )  ∨  𝐷  ∈  ( 𝐵 𝐼 𝐶 ) ) )  | 
						
						
							| 21 | 
							
								3
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐺  ∈  TarskiG )  | 
						
						
							| 22 | 
							
								4
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐴  ∈  𝑃 )  | 
						
						
							| 23 | 
							
								5
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐵  ∈  𝑃 )  | 
						
						
							| 24 | 
							
								7
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐷  ∈  𝑃 )  | 
						
						
							| 25 | 
							
								6
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐶  ∈  𝑃 )  | 
						
						
							| 26 | 
							
								10
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐵  ∈  ( 𝐴 𝐼 𝐷 ) )  | 
						
						
							| 27 | 
							
								
							 | 
							simpr | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  | 
						
						
							| 28 | 
							
								1 11 2 21 22 23 24 25 26 27
							 | 
							tgbtwnexch3 | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  𝐷  ∈  ( 𝐵 𝐼 𝐶 ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							olcd | 
							⊢ ( ( 𝜑  ∧  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) )  →  ( 𝐶  ∈  ( 𝐵 𝐼 𝐷 )  ∨  𝐷  ∈  ( 𝐵 𝐼 𝐶 ) ) )  | 
						
						
							| 30 | 
							
								1 2 3 4 5 6 7 8 9 10
							 | 
							tgbtwnconn1 | 
							⊢ ( 𝜑  →  ( 𝐶  ∈  ( 𝐴 𝐼 𝐷 )  ∨  𝐷  ∈  ( 𝐴 𝐼 𝐶 ) ) )  | 
						
						
							| 31 | 
							
								20 29 30
							 | 
							mpjaodan | 
							⊢ ( 𝜑  →  ( 𝐶  ∈  ( 𝐵 𝐼 𝐷 )  ∨  𝐷  ∈  ( 𝐵 𝐼 𝐶 ) ) )  |