| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdpglem.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | mapdpglem.m | ⊢ 𝑀  =  ( ( mapd ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | mapdpglem.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 4 |  | mapdpglem.v | ⊢ 𝑉  =  ( Base ‘ 𝑈 ) | 
						
							| 5 |  | mapdpglem.s | ⊢  −   =  ( -g ‘ 𝑈 ) | 
						
							| 6 |  | mapdpglem.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑈 ) | 
						
							| 7 |  | mapdpglem.c | ⊢ 𝐶  =  ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 |  | mapdpglem.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 9 |  | mapdpglem.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 10 |  | mapdpglem.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 11 |  | mapdpglem1.p | ⊢  ⊕   =  ( LSSum ‘ 𝐶 ) | 
						
							| 12 |  | mapdpglem2.j | ⊢ 𝐽  =  ( LSpan ‘ 𝐶 ) | 
						
							| 13 |  | mapdpglem3.f | ⊢ 𝐹  =  ( Base ‘ 𝐶 ) | 
						
							| 14 |  | mapdpglem3.te | ⊢ ( 𝜑  →  𝑡  ∈  ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) )  ⊕  ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) ) ) | 
						
							| 15 |  | mapdpglem3.a | ⊢ 𝐴  =  ( Scalar ‘ 𝑈 ) | 
						
							| 16 |  | mapdpglem3.b | ⊢ 𝐵  =  ( Base ‘ 𝐴 ) | 
						
							| 17 |  | mapdpglem3.t | ⊢  ·   =  (  ·𝑠  ‘ 𝐶 ) | 
						
							| 18 |  | mapdpglem3.r | ⊢ 𝑅  =  ( -g ‘ 𝐶 ) | 
						
							| 19 |  | mapdpglem3.g | ⊢ ( 𝜑  →  𝐺  ∈  𝐹 ) | 
						
							| 20 |  | mapdpglem3.e | ⊢ ( 𝜑  →  ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) )  =  ( 𝐽 ‘ { 𝐺 } ) ) | 
						
							| 21 |  | mapdpglem4.q | ⊢ 𝑄  =  ( 0g ‘ 𝑈 ) | 
						
							| 22 |  | mapdpglem.ne | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 23 |  | mapdpglem4.jt | ⊢ ( 𝜑  →  ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋  −  𝑌 ) } ) )  =  ( 𝐽 ‘ { 𝑡 } ) ) | 
						
							| 24 |  | mapdpglem4.z | ⊢  0   =  ( 0g ‘ 𝐴 ) | 
						
							| 25 |  | mapdpglem4.g4 | ⊢ ( 𝜑  →  𝑔  ∈  𝐵 ) | 
						
							| 26 |  | mapdpglem4.z4 | ⊢ ( 𝜑  →  𝑧  ∈  ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) ) | 
						
							| 27 |  | mapdpglem4.t4 | ⊢ ( 𝜑  →  𝑡  =  ( ( 𝑔  ·  𝐺 ) 𝑅 𝑧 ) ) | 
						
							| 28 |  | mapdpglem4.xn | ⊢ ( 𝜑  →  𝑋  ≠  𝑄 ) | 
						
							| 29 |  | mapdpglem4.g0 | ⊢ ( 𝜑  →  𝑔  =   0  ) | 
						
							| 30 | 1 3 8 | dvhlmod | ⊢ ( 𝜑  →  𝑈  ∈  LMod ) | 
						
							| 31 |  | eqid | ⊢ ( +g ‘ 𝑈 )  =  ( +g ‘ 𝑈 ) | 
						
							| 32 | 4 31 5 | lmodvnpcan | ⊢ ( ( 𝑈  ∈  LMod  ∧  𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑉 )  →  ( ( 𝑋  −  𝑌 ) ( +g ‘ 𝑈 ) 𝑌 )  =  𝑋 ) | 
						
							| 33 | 30 9 10 32 | syl3anc | ⊢ ( 𝜑  →  ( ( 𝑋  −  𝑌 ) ( +g ‘ 𝑈 ) 𝑌 )  =  𝑋 ) | 
						
							| 34 |  | eqid | ⊢ ( LSubSp ‘ 𝑈 )  =  ( LSubSp ‘ 𝑈 ) | 
						
							| 35 | 4 34 6 | lspsncl | ⊢ ( ( 𝑈  ∈  LMod  ∧  𝑌  ∈  𝑉 )  →  ( 𝑁 ‘ { 𝑌 } )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 36 | 30 10 35 | syl2anc | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 37 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | mapdpglem8 | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑋  −  𝑌 ) } )  ⊆  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 38 | 4 5 | lmodvsubcl | ⊢ ( ( 𝑈  ∈  LMod  ∧  𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑉 )  →  ( 𝑋  −  𝑌 )  ∈  𝑉 ) | 
						
							| 39 | 30 9 10 38 | syl3anc | ⊢ ( 𝜑  →  ( 𝑋  −  𝑌 )  ∈  𝑉 ) | 
						
							| 40 | 4 6 | lspsnid | ⊢ ( ( 𝑈  ∈  LMod  ∧  ( 𝑋  −  𝑌 )  ∈  𝑉 )  →  ( 𝑋  −  𝑌 )  ∈  ( 𝑁 ‘ { ( 𝑋  −  𝑌 ) } ) ) | 
						
							| 41 | 30 39 40 | syl2anc | ⊢ ( 𝜑  →  ( 𝑋  −  𝑌 )  ∈  ( 𝑁 ‘ { ( 𝑋  −  𝑌 ) } ) ) | 
						
							| 42 | 37 41 | sseldd | ⊢ ( 𝜑  →  ( 𝑋  −  𝑌 )  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 43 | 4 6 | lspsnid | ⊢ ( ( 𝑈  ∈  LMod  ∧  𝑌  ∈  𝑉 )  →  𝑌  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 44 | 30 10 43 | syl2anc | ⊢ ( 𝜑  →  𝑌  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 45 | 31 34 | lssvacl | ⊢ ( ( ( 𝑈  ∈  LMod  ∧  ( 𝑁 ‘ { 𝑌 } )  ∈  ( LSubSp ‘ 𝑈 ) )  ∧  ( ( 𝑋  −  𝑌 )  ∈  ( 𝑁 ‘ { 𝑌 } )  ∧  𝑌  ∈  ( 𝑁 ‘ { 𝑌 } ) ) )  →  ( ( 𝑋  −  𝑌 ) ( +g ‘ 𝑈 ) 𝑌 )  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 46 | 30 36 42 44 45 | syl22anc | ⊢ ( 𝜑  →  ( ( 𝑋  −  𝑌 ) ( +g ‘ 𝑈 ) 𝑌 )  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 47 | 33 46 | eqeltrrd | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑁 ‘ { 𝑌 } ) ) |