Metamath Proof Explorer
		
		
		
		Description:  The half-line relation is reflexive.  Theorem 6.5 of Schwabhauser
         p. 44.  (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 | ⊢ ( 𝜑  →  𝐴  ∈  𝑃 ) | 
					
						|  |  | ishlg.b | ⊢ ( 𝜑  →  𝐵  ∈  𝑃 ) | 
					
						|  |  | ishlg.c | ⊢ ( 𝜑  →  𝐶  ∈  𝑃 ) | 
					
						|  |  | hlln.1 | ⊢ ( 𝜑  →  𝐺  ∈  TarskiG ) | 
					
						|  |  | hlid.1 | ⊢ ( 𝜑  →  𝐴  ≠  𝐶 ) | 
				
					|  | Assertion | hlid | ⊢  ( 𝜑  →  𝐴 ( 𝐾 ‘ 𝐶 ) 𝐴 ) | 
			
		
		
			
				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 | ⊢ ( 𝜑  →  𝐴  ∈  𝑃 ) | 
						
							| 5 |  | ishlg.b | ⊢ ( 𝜑  →  𝐵  ∈  𝑃 ) | 
						
							| 6 |  | ishlg.c | ⊢ ( 𝜑  →  𝐶  ∈  𝑃 ) | 
						
							| 7 |  | hlln.1 | ⊢ ( 𝜑  →  𝐺  ∈  TarskiG ) | 
						
							| 8 |  | hlid.1 | ⊢ ( 𝜑  →  𝐴  ≠  𝐶 ) | 
						
							| 9 |  | eqid | ⊢ ( dist ‘ 𝐺 )  =  ( dist ‘ 𝐺 ) | 
						
							| 10 | 1 9 2 7 6 4 | tgbtwntriv2 | ⊢ ( 𝜑  →  𝐴  ∈  ( 𝐶 𝐼 𝐴 ) ) | 
						
							| 11 | 10 | olcd | ⊢ ( 𝜑  →  ( 𝐴  ∈  ( 𝐶 𝐼 𝐴 )  ∨  𝐴  ∈  ( 𝐶 𝐼 𝐴 ) ) ) | 
						
							| 12 | 1 2 3 4 4 6 7 | ishlg | ⊢ ( 𝜑  →  ( 𝐴 ( 𝐾 ‘ 𝐶 ) 𝐴  ↔  ( 𝐴  ≠  𝐶  ∧  𝐴  ≠  𝐶  ∧  ( 𝐴  ∈  ( 𝐶 𝐼 𝐴 )  ∨  𝐴  ∈  ( 𝐶 𝐼 𝐴 ) ) ) ) ) | 
						
							| 13 | 8 8 11 12 | mpbir3and | ⊢ ( 𝜑  →  𝐴 ( 𝐾 ‘ 𝐶 ) 𝐴 ) |