| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ismid.p | ⊢ 𝑃  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | ismid.d | ⊢  −   =  ( dist ‘ 𝐺 ) | 
						
							| 3 |  | ismid.i | ⊢ 𝐼  =  ( Itv ‘ 𝐺 ) | 
						
							| 4 |  | ismid.g | ⊢ ( 𝜑  →  𝐺  ∈  TarskiG ) | 
						
							| 5 |  | ismid.1 | ⊢ ( 𝜑  →  𝐺 DimTarskiG≥ 2 ) | 
						
							| 6 |  | lmif.m | ⊢ 𝑀  =  ( ( lInvG ‘ 𝐺 ) ‘ 𝐷 ) | 
						
							| 7 |  | lmif.l | ⊢ 𝐿  =  ( LineG ‘ 𝐺 ) | 
						
							| 8 |  | lmif.d | ⊢ ( 𝜑  →  𝐷  ∈  ran  𝐿 ) | 
						
							| 9 |  | lmicl.1 | ⊢ ( 𝜑  →  𝐴  ∈  𝑃 ) | 
						
							| 10 |  | lmimid.s | ⊢ 𝑆  =  ( ( pInvG ‘ 𝐺 ) ‘ 𝐵 ) | 
						
							| 11 |  | lmimid.r | ⊢ ( 𝜑  →  〈“ 𝐴 𝐵 𝐶 ”〉  ∈  ( ∟G ‘ 𝐺 ) ) | 
						
							| 12 |  | lmimid.a | ⊢ ( 𝜑  →  𝐴  ∈  𝐷 ) | 
						
							| 13 |  | lmimid.b | ⊢ ( 𝜑  →  𝐵  ∈  𝐷 ) | 
						
							| 14 |  | lmimid.c | ⊢ ( 𝜑  →  𝐶  ∈  𝑃 ) | 
						
							| 15 |  | lmimid.d | ⊢ ( 𝜑  →  𝐴  ≠  𝐵 ) | 
						
							| 16 | 10 | a1i | ⊢ ( 𝜑  →  𝑆  =  ( ( pInvG ‘ 𝐺 ) ‘ 𝐵 ) ) | 
						
							| 17 | 16 | fveq1d | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( ( ( pInvG ‘ 𝐺 ) ‘ 𝐵 ) ‘ 𝐶 ) ) | 
						
							| 18 |  | eqid | ⊢ ( pInvG ‘ 𝐺 )  =  ( pInvG ‘ 𝐺 ) | 
						
							| 19 | 1 7 3 4 8 13 | tglnpt | ⊢ ( 𝜑  →  𝐵  ∈  𝑃 ) | 
						
							| 20 | 1 2 3 7 18 4 19 10 14 | mircl | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  ∈  𝑃 ) | 
						
							| 21 | 1 2 3 4 5 14 20 18 19 | ismidb | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  =  ( ( ( pInvG ‘ 𝐺 ) ‘ 𝐵 ) ‘ 𝐶 )  ↔  ( 𝐶 ( midG ‘ 𝐺 ) ( 𝑆 ‘ 𝐶 ) )  =  𝐵 ) ) | 
						
							| 22 | 17 21 | mpbid | ⊢ ( 𝜑  →  ( 𝐶 ( midG ‘ 𝐺 ) ( 𝑆 ‘ 𝐶 ) )  =  𝐵 ) | 
						
							| 23 | 22 13 | eqeltrd | ⊢ ( 𝜑  →  ( 𝐶 ( midG ‘ 𝐺 ) ( 𝑆 ‘ 𝐶 ) )  ∈  𝐷 ) | 
						
							| 24 |  | df-ne | ⊢ ( 𝐶  ≠  ( 𝑆 ‘ 𝐶 )  ↔  ¬  𝐶  =  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 25 | 4 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐺  ∈  TarskiG ) | 
						
							| 26 | 8 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐷  ∈  ran  𝐿 ) | 
						
							| 27 | 14 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐶  ∈  𝑃 ) | 
						
							| 28 | 20 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  ( 𝑆 ‘ 𝐶 )  ∈  𝑃 ) | 
						
							| 29 |  | simpr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 30 | 1 3 7 25 27 28 29 | tgelrnln | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) )  ∈  ran  𝐿 ) | 
						
							| 31 | 13 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐵  ∈  𝐷 ) | 
						
							| 32 | 19 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐵  ∈  𝑃 ) | 
						
							| 33 | 1 2 3 4 5 14 20 | midbtwn | ⊢ ( 𝜑  →  ( 𝐶 ( midG ‘ 𝐺 ) ( 𝑆 ‘ 𝐶 ) )  ∈  ( 𝐶 𝐼 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 34 | 22 33 | eqeltrrd | ⊢ ( 𝜑  →  𝐵  ∈  ( 𝐶 𝐼 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 35 | 34 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐵  ∈  ( 𝐶 𝐼 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 36 | 1 3 7 25 27 28 32 29 35 | btwnlng1 | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐵  ∈  ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 37 | 31 36 | elind | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐵  ∈  ( 𝐷  ∩  ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 38 | 12 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐴  ∈  𝐷 ) | 
						
							| 39 | 1 3 7 25 27 28 29 | tglinerflx1 | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐶  ∈  ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 40 | 15 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐴  ≠  𝐵 ) | 
						
							| 41 | 1 2 3 7 18 4 19 10 14 | mirinv | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  =  𝐶  ↔  𝐵  =  𝐶 ) ) | 
						
							| 42 |  | eqcom | ⊢ ( 𝐵  =  𝐶  ↔  𝐶  =  𝐵 ) | 
						
							| 43 | 41 42 | bitrdi | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  =  𝐶  ↔  𝐶  =  𝐵 ) ) | 
						
							| 44 | 43 | biimpar | ⊢ ( ( 𝜑  ∧  𝐶  =  𝐵 )  →  ( 𝑆 ‘ 𝐶 )  =  𝐶 ) | 
						
							| 45 | 44 | eqcomd | ⊢ ( ( 𝜑  ∧  𝐶  =  𝐵 )  →  𝐶  =  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 46 | 45 | ex | ⊢ ( 𝜑  →  ( 𝐶  =  𝐵  →  𝐶  =  ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 47 | 46 | necon3d | ⊢ ( 𝜑  →  ( 𝐶  ≠  ( 𝑆 ‘ 𝐶 )  →  𝐶  ≠  𝐵 ) ) | 
						
							| 48 | 47 | imp | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐶  ≠  𝐵 ) | 
						
							| 49 | 11 | adantr | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  〈“ 𝐴 𝐵 𝐶 ”〉  ∈  ( ∟G ‘ 𝐺 ) ) | 
						
							| 50 | 1 2 3 7 25 26 30 37 38 39 40 48 49 | ragperp | ⊢ ( ( 𝜑  ∧  𝐶  ≠  ( 𝑆 ‘ 𝐶 ) )  →  𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 51 | 50 | ex | ⊢ ( 𝜑  →  ( 𝐶  ≠  ( 𝑆 ‘ 𝐶 )  →  𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 52 | 24 51 | biimtrrid | ⊢ ( 𝜑  →  ( ¬  𝐶  =  ( 𝑆 ‘ 𝐶 )  →  𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 53 | 52 | orrd | ⊢ ( 𝜑  →  ( 𝐶  =  ( 𝑆 ‘ 𝐶 )  ∨  𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 54 | 53 | orcomd | ⊢ ( 𝜑  →  ( 𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) )  ∨  𝐶  =  ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 55 | 1 2 3 4 5 6 7 8 14 20 | islmib | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  =  ( 𝑀 ‘ 𝐶 )  ↔  ( ( 𝐶 ( midG ‘ 𝐺 ) ( 𝑆 ‘ 𝐶 ) )  ∈  𝐷  ∧  ( 𝐷 ( ⟂G ‘ 𝐺 ) ( 𝐶 𝐿 ( 𝑆 ‘ 𝐶 ) )  ∨  𝐶  =  ( 𝑆 ‘ 𝐶 ) ) ) ) ) | 
						
							| 56 | 23 54 55 | mpbir2and | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( 𝑀 ‘ 𝐶 ) ) | 
						
							| 57 | 56 | eqcomd | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝐶 )  =  ( 𝑆 ‘ 𝐶 ) ) |