| 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 | 1 2 3 4 5 6 7 8 | lmif1o | ⊢ ( 𝜑  →  𝑀 : 𝑃 –1-1-onto→ 𝑃 ) | 
						
							| 10 | 4 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  𝐺  ∈  TarskiG ) | 
						
							| 11 | 5 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  𝐺 DimTarskiG≥ 2 ) | 
						
							| 12 | 8 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  𝐷  ∈  ran  𝐿 ) | 
						
							| 13 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  𝑎  ∈  𝑃 ) | 
						
							| 14 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  𝑏  ∈  𝑃 ) | 
						
							| 15 | 1 2 3 10 11 6 7 12 13 14 | lmiiso | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑃  ∧  𝑏  ∈  𝑃 ) )  →  ( ( 𝑀 ‘ 𝑎 )  −  ( 𝑀 ‘ 𝑏 ) )  =  ( 𝑎  −  𝑏 ) ) | 
						
							| 16 | 15 | ralrimivva | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  𝑃 ∀ 𝑏  ∈  𝑃 ( ( 𝑀 ‘ 𝑎 )  −  ( 𝑀 ‘ 𝑏 ) )  =  ( 𝑎  −  𝑏 ) ) | 
						
							| 17 | 1 2 | ismot | ⊢ ( 𝐺  ∈  TarskiG  →  ( 𝑀  ∈  ( 𝐺 Ismt 𝐺 )  ↔  ( 𝑀 : 𝑃 –1-1-onto→ 𝑃  ∧  ∀ 𝑎  ∈  𝑃 ∀ 𝑏  ∈  𝑃 ( ( 𝑀 ‘ 𝑎 )  −  ( 𝑀 ‘ 𝑏 ) )  =  ( 𝑎  −  𝑏 ) ) ) ) | 
						
							| 18 | 4 17 | syl | ⊢ ( 𝜑  →  ( 𝑀  ∈  ( 𝐺 Ismt 𝐺 )  ↔  ( 𝑀 : 𝑃 –1-1-onto→ 𝑃  ∧  ∀ 𝑎  ∈  𝑃 ∀ 𝑏  ∈  𝑃 ( ( 𝑀 ‘ 𝑎 )  −  ( 𝑀 ‘ 𝑏 ) )  =  ( 𝑎  −  𝑏 ) ) ) ) | 
						
							| 19 | 9 16 18 | mpbir2and | ⊢ ( 𝜑  →  𝑀  ∈  ( 𝐺 Ismt 𝐺 ) ) |