| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdh8a.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | mapdh8a.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | mapdh8a.v | ⊢ 𝑉  =  ( Base ‘ 𝑈 ) | 
						
							| 4 |  | mapdh8a.s | ⊢  −   =  ( -g ‘ 𝑈 ) | 
						
							| 5 |  | mapdh8a.o | ⊢  0   =  ( 0g ‘ 𝑈 ) | 
						
							| 6 |  | mapdh8a.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑈 ) | 
						
							| 7 |  | mapdh8a.c | ⊢ 𝐶  =  ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 |  | mapdh8a.d | ⊢ 𝐷  =  ( Base ‘ 𝐶 ) | 
						
							| 9 |  | mapdh8a.r | ⊢ 𝑅  =  ( -g ‘ 𝐶 ) | 
						
							| 10 |  | mapdh8a.q | ⊢ 𝑄  =  ( 0g ‘ 𝐶 ) | 
						
							| 11 |  | mapdh8a.j | ⊢ 𝐽  =  ( LSpan ‘ 𝐶 ) | 
						
							| 12 |  | mapdh8a.m | ⊢ 𝑀  =  ( ( mapd ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 13 |  | mapdh8a.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 |  | mapdh8a.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 15 |  | mapdh8ab.f | ⊢ ( 𝜑  →  𝐹  ∈  𝐷 ) | 
						
							| 16 |  | mapdh8ab.mn | ⊢ ( 𝜑  →  ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) )  =  ( 𝐽 ‘ { 𝐹 } ) ) | 
						
							| 17 |  | mapdh8ab.eg | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑋 ,  𝐹 ,  𝑌 〉 )  =  𝐺 ) | 
						
							| 18 |  | mapdh8ab.ee | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑋 ,  𝐹 ,  𝑍 〉 )  =  𝐸 ) | 
						
							| 19 |  | mapdh8ab.x | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 20 |  | mapdh8ab.y | ⊢ ( 𝜑  →  𝑌  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 21 |  | mapdh8ab.z | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 22 |  | mapdh8ab.t | ⊢ ( 𝜑  →  𝑇  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 23 |  | mapdh8ab.yz | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 24 |  | mapdh8ab.xn | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) | 
						
							| 25 |  | mapdh8ab.yn | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  =  ( 𝑁 ‘ { 𝑇 } ) ) | 
						
							| 26 | 1 2 14 | dvhlvec | ⊢ ( 𝜑  →  𝑈  ∈  LVec ) | 
						
							| 27 | 19 | eldifad | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 28 | 20 | eldifad | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 29 | 21 | eldifad | ⊢ ( 𝜑  →  𝑍  ∈  𝑉 ) | 
						
							| 30 | 3 6 26 27 28 29 24 | lspindpi | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } )  ∧  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) ) | 
						
							| 31 | 30 | simprd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 32 | 31 | necomd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑍 } )  ≠  ( 𝑁 ‘ { 𝑋 } ) ) | 
						
							| 33 | 32 25 | neeqtrd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑍 } )  ≠  ( 𝑁 ‘ { 𝑇 } ) ) | 
						
							| 34 | 25 | sseq1d | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  ⊆  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ↔  ( 𝑁 ‘ { 𝑇 } )  ⊆  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) ) | 
						
							| 35 |  | eqid | ⊢ ( LSubSp ‘ 𝑈 )  =  ( LSubSp ‘ 𝑈 ) | 
						
							| 36 | 1 2 14 | dvhlmod | ⊢ ( 𝜑  →  𝑈  ∈  LMod ) | 
						
							| 37 | 3 35 6 36 28 29 | lspprcl | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 38 | 3 35 6 36 37 27 | ellspsn5b | ⊢ ( 𝜑  →  ( 𝑋  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ↔  ( 𝑁 ‘ { 𝑋 } )  ⊆  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) ) | 
						
							| 39 | 22 | eldifad | ⊢ ( 𝜑  →  𝑇  ∈  𝑉 ) | 
						
							| 40 | 3 35 6 36 37 39 | ellspsn5b | ⊢ ( 𝜑  →  ( 𝑇  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ↔  ( 𝑁 ‘ { 𝑇 } )  ⊆  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) ) | 
						
							| 41 | 34 38 40 | 3bitr4d | ⊢ ( 𝜑  →  ( 𝑋  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ↔  𝑇  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) ) | 
						
							| 42 | 24 41 | mtbid | ⊢ ( 𝜑  →  ¬  𝑇  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) | 
						
							| 43 | 26 | adantr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑈  ∈  LVec ) | 
						
							| 44 | 20 | adantr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑌  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 45 | 39 | adantr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑇  ∈  𝑉 ) | 
						
							| 46 | 29 | adantr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑍  ∈  𝑉 ) | 
						
							| 47 | 23 | adantr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  ( 𝑁 ‘ { 𝑌 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 48 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) ) | 
						
							| 49 |  | prcom | ⊢ { 𝑍 ,  𝑇 }  =  { 𝑇 ,  𝑍 } | 
						
							| 50 | 49 | fveq2i | ⊢ ( 𝑁 ‘ { 𝑍 ,  𝑇 } )  =  ( 𝑁 ‘ { 𝑇 ,  𝑍 } ) | 
						
							| 51 | 48 50 | eleqtrdi | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑌  ∈  ( 𝑁 ‘ { 𝑇 ,  𝑍 } ) ) | 
						
							| 52 | 3 5 6 43 44 45 46 47 51 | lspexch | ⊢ ( ( 𝜑  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) )  →  𝑇  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) | 
						
							| 53 | 42 52 | mtand | ⊢ ( 𝜑  →  ¬  𝑌  ∈  ( 𝑁 ‘ { 𝑍 ,  𝑇 } ) ) | 
						
							| 54 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 33 22 53 24 | mapdh8aa | ⊢ ( 𝜑  →  ( 𝐼 ‘ 〈 𝑌 ,  𝐺 ,  𝑇 〉 )  =  ( 𝐼 ‘ 〈 𝑍 ,  𝐸 ,  𝑇 〉 ) ) |