| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdh75.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | mapdh75.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | mapdh75.v | ⊢ 𝑉  =  ( Base ‘ 𝑈 ) | 
						
							| 4 |  | mapdh75.s | ⊢  −   =  ( -g ‘ 𝑈 ) | 
						
							| 5 |  | mapdh75.o | ⊢  0   =  ( 0g ‘ 𝑈 ) | 
						
							| 6 |  | mapdh75.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑈 ) | 
						
							| 7 |  | mapdh75.c | ⊢ 𝐶  =  ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 |  | mapdh75.d | ⊢ 𝐷  =  ( Base ‘ 𝐶 ) | 
						
							| 9 |  | mapdh75.r | ⊢ 𝑅  =  ( -g ‘ 𝐶 ) | 
						
							| 10 |  | mapdh75.q | ⊢ 𝑄  =  ( 0g ‘ 𝐶 ) | 
						
							| 11 |  | mapdh75.j | ⊢ 𝐽  =  ( LSpan ‘ 𝐶 ) | 
						
							| 12 |  | mapdh75.m | ⊢ 𝑀  =  ( ( mapd ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 13 |  | mapdh75.i | ⊢ 𝐼  =  ( 𝑥  ∈  V  ↦  if ( ( 2nd  ‘ 𝑥 )  =   0  ,  𝑄 ,  ( ℩ ℎ  ∈  𝐷 ( ( 𝑀 ‘ ( 𝑁 ‘ { ( 2nd  ‘ 𝑥 ) } ) )  =  ( 𝐽 ‘ { ℎ } )  ∧  ( 𝑀 ‘ ( 𝑁 ‘ { ( ( 1st  ‘ ( 1st  ‘ 𝑥 ) )  −  ( 2nd  ‘ 𝑥 ) ) } ) )  =  ( 𝐽 ‘ { ( ( 2nd  ‘ ( 1st  ‘ 𝑥 ) ) 𝑅 ℎ ) } ) ) ) ) ) | 
						
							| 14 |  | mapdh75.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 15 |  | mapdh75.f | ⊢ ( 𝜑  →  𝐹  ∈  𝐷 ) | 
						
							| 16 |  | mapdh75.mn | ⊢ ( 𝜑  →  ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) )  =  ( 𝐽 ‘ { 𝐹 } ) ) | 
						
							| 17 |  | mapdh75b | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑋 ,  𝐹 ,  𝑍 〉 )  =  𝐸 ) | 
						
							| 18 |  | mapdh75e.ne | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 19 |  | mapdh75e.x | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 20 |  | mapdh75e.z | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 21 | 20 | eldifad | ⊢ ( 𝜑  →  𝑍  ∈  𝑉 ) | 
						
							| 22 | 10 13 1 12 2 3 4 5 6 7 8 9 11 14 15 16 19 21 18 | mapdhcl | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑋 ,  𝐹 ,  𝑍 〉 )  ∈  𝐷 ) | 
						
							| 23 | 17 22 | eqeltrrd | ⊢ ( 𝜑  →  𝐸  ∈  𝐷 ) | 
						
							| 24 | 10 13 1 12 2 3 4 5 6 7 8 9 11 14 15 16 19 20 23 18 | mapdheq2 | ⊢ ( 𝜑  →  ( ( 𝐼 ‘ 〈 𝑋 ,  𝐹 ,  𝑍 〉 )  =  𝐸  →  ( 𝐼 ‘ 〈 𝑍 ,  𝐸 ,  𝑋 〉 )  =  𝐹 ) ) | 
						
							| 25 | 17 24 | mpd | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑍 ,  𝐸 ,  𝑋 〉 )  =  𝐹 ) |