| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mirval.p | ⊢ 𝑃  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | mirval.d | ⊢  −   =  ( dist ‘ 𝐺 ) | 
						
							| 3 |  | mirval.i | ⊢ 𝐼  =  ( Itv ‘ 𝐺 ) | 
						
							| 4 |  | mirval.l | ⊢ 𝐿  =  ( LineG ‘ 𝐺 ) | 
						
							| 5 |  | mirval.s | ⊢ 𝑆  =  ( pInvG ‘ 𝐺 ) | 
						
							| 6 |  | mirval.g | ⊢ ( 𝜑  →  𝐺  ∈  TarskiG ) | 
						
							| 7 |  | mirval.a | ⊢ ( 𝜑  →  𝐴  ∈  𝑃 ) | 
						
							| 8 |  | mirfv.m | ⊢ 𝑀  =  ( 𝑆 ‘ 𝐴 ) | 
						
							| 9 |  | mirmir.b | ⊢ ( 𝜑  →  𝐵  ∈  𝑃 ) | 
						
							| 10 |  | mireq.c | ⊢ ( 𝜑  →  𝐶  ∈  𝑃 ) | 
						
							| 11 |  | mireq.d | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝐵 )  =  ( 𝑀 ‘ 𝐶 ) ) | 
						
							| 12 | 1 2 3 4 5 6 7 8 10 | mircl | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝐶 )  ∈  𝑃 ) | 
						
							| 13 | 1 2 3 4 5 6 7 8 9 | mirfv | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝐵 )  =  ( ℩ 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) ) ) | 
						
							| 14 | 13 11 | eqtr3d | ⊢ ( 𝜑  →  ( ℩ 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) )  =  ( 𝑀 ‘ 𝐶 ) ) | 
						
							| 15 | 1 2 3 6 9 7 | mirreu3 | ⊢ ( 𝜑  →  ∃! 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) ) | 
						
							| 16 |  | oveq2 | ⊢ ( 𝑧  =  ( 𝑀 ‘ 𝐶 )  →  ( 𝐴  −  𝑧 )  =  ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 17 | 16 | eqeq1d | ⊢ ( 𝑧  =  ( 𝑀 ‘ 𝐶 )  →  ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ↔  ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 ) ) ) | 
						
							| 18 |  | oveq1 | ⊢ ( 𝑧  =  ( 𝑀 ‘ 𝐶 )  →  ( 𝑧 𝐼 𝐵 )  =  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) ) | 
						
							| 19 | 18 | eleq2d | ⊢ ( 𝑧  =  ( 𝑀 ‘ 𝐶 )  →  ( 𝐴  ∈  ( 𝑧 𝐼 𝐵 )  ↔  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) ) ) | 
						
							| 20 | 17 19 | anbi12d | ⊢ ( 𝑧  =  ( 𝑀 ‘ 𝐶 )  →  ( ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) )  ↔  ( ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) ) ) ) | 
						
							| 21 | 20 | riota2 | ⊢ ( ( ( 𝑀 ‘ 𝐶 )  ∈  𝑃  ∧  ∃! 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) )  →  ( ( ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) )  ↔  ( ℩ 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) )  =  ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 22 | 12 15 21 | syl2anc | ⊢ ( 𝜑  →  ( ( ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) )  ↔  ( ℩ 𝑧  ∈  𝑃 ( ( 𝐴  −  𝑧 )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( 𝑧 𝐼 𝐵 ) ) )  =  ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 23 | 14 22 | mpbird | ⊢ ( 𝜑  →  ( ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 )  ∧  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) ) ) | 
						
							| 24 | 23 | simpld | ⊢ ( 𝜑  →  ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) )  =  ( 𝐴  −  𝐵 ) ) | 
						
							| 25 | 24 | eqcomd | ⊢ ( 𝜑  →  ( 𝐴  −  𝐵 )  =  ( 𝐴  −  ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 26 | 23 | simprd | ⊢ ( 𝜑  →  𝐴  ∈  ( ( 𝑀 ‘ 𝐶 ) 𝐼 𝐵 ) ) | 
						
							| 27 | 1 2 3 6 12 7 9 26 | tgbtwncom | ⊢ ( 𝜑  →  𝐴  ∈  ( 𝐵 𝐼 ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 28 | 1 2 3 4 5 6 7 8 12 9 25 27 | ismir | ⊢ ( 𝜑  →  𝐵  =  ( 𝑀 ‘ ( 𝑀 ‘ 𝐶 ) ) ) | 
						
							| 29 | 1 2 3 4 5 6 7 8 10 | mirmir | ⊢ ( 𝜑  →  ( 𝑀 ‘ ( 𝑀 ‘ 𝐶 ) )  =  𝐶 ) | 
						
							| 30 | 28 29 | eqtrd | ⊢ ( 𝜑  →  𝐵  =  𝐶 ) |