| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lclkrlem2m.v | ⊢ 𝑉  =  ( Base ‘ 𝑈 ) | 
						
							| 2 |  | lclkrlem2m.t | ⊢  ·   =  (  ·𝑠  ‘ 𝑈 ) | 
						
							| 3 |  | lclkrlem2m.s | ⊢ 𝑆  =  ( Scalar ‘ 𝑈 ) | 
						
							| 4 |  | lclkrlem2m.q | ⊢  ×   =  ( .r ‘ 𝑆 ) | 
						
							| 5 |  | lclkrlem2m.z | ⊢  0   =  ( 0g ‘ 𝑆 ) | 
						
							| 6 |  | lclkrlem2m.i | ⊢ 𝐼  =  ( invr ‘ 𝑆 ) | 
						
							| 7 |  | lclkrlem2m.m | ⊢  −   =  ( -g ‘ 𝑈 ) | 
						
							| 8 |  | lclkrlem2m.f | ⊢ 𝐹  =  ( LFnl ‘ 𝑈 ) | 
						
							| 9 |  | lclkrlem2m.d | ⊢ 𝐷  =  ( LDual ‘ 𝑈 ) | 
						
							| 10 |  | lclkrlem2m.p | ⊢  +   =  ( +g ‘ 𝐷 ) | 
						
							| 11 |  | lclkrlem2m.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 12 |  | lclkrlem2m.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 13 |  | lclkrlem2m.e | ⊢ ( 𝜑  →  𝐸  ∈  𝐹 ) | 
						
							| 14 |  | lclkrlem2m.g | ⊢ ( 𝜑  →  𝐺  ∈  𝐹 ) | 
						
							| 15 |  | lclkrlem2n.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑈 ) | 
						
							| 16 |  | lclkrlem2n.l | ⊢ 𝐿  =  ( LKer ‘ 𝑈 ) | 
						
							| 17 |  | lclkrlem2o.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 18 |  | lclkrlem2o.o | ⊢  ⊥   =  ( ( ocH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 19 |  | lclkrlem2o.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 20 |  | lclkrlem2o.a | ⊢  ⊕   =  ( LSSum ‘ 𝑈 ) | 
						
							| 21 |  | lclkrlem2o.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 22 |  | lclkrlem2q.le | ⊢ ( 𝜑  →  ( 𝐿 ‘ 𝐸 )  =  (  ⊥  ‘ { 𝑋 } ) ) | 
						
							| 23 |  | lclkrlem2q.lg | ⊢ ( 𝜑  →  ( 𝐿 ‘ 𝐺 )  =  (  ⊥  ‘ { 𝑌 } ) ) | 
						
							| 24 |  | lclkrlem2v.j | ⊢ ( 𝜑  →  ( ( 𝐸  +  𝐺 ) ‘ 𝑋 )  =   0  ) | 
						
							| 25 |  | lclkrlem2v.k | ⊢ ( 𝜑  →  ( ( 𝐸  +  𝐺 ) ‘ 𝑌 )  =   0  ) | 
						
							| 26 | 17 19 21 | dvhlmod | ⊢ ( 𝜑  →  𝑈  ∈  LMod ) | 
						
							| 27 | 8 9 10 26 13 14 | ldualvaddcl | ⊢ ( 𝜑  →  ( 𝐸  +  𝐺 )  ∈  𝐹 ) | 
						
							| 28 | 1 8 16 26 27 | lkrssv | ⊢ ( 𝜑  →  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ⊆  𝑉 ) | 
						
							| 29 |  | eqid | ⊢ ( LSubSp ‘ 𝑈 )  =  ( LSubSp ‘ 𝑈 ) | 
						
							| 30 | 1 29 15 26 11 12 | lspprcl | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 31 |  | eqid | ⊢ ( ( DIsoH ‘ 𝐾 ) ‘ 𝑊 )  =  ( ( DIsoH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 32 | 17 19 1 15 31 21 11 12 | dihprrn | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ran  ( ( DIsoH ‘ 𝐾 ) ‘ 𝑊 ) ) | 
						
							| 33 | 1 29 | lssss | ⊢ ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ( LSubSp ‘ 𝑈 )  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  𝑉 ) | 
						
							| 34 | 30 33 | syl | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  𝑉 ) | 
						
							| 35 | 17 31 19 1 18 21 34 | dochoccl | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ran  ( ( DIsoH ‘ 𝐾 ) ‘ 𝑊 )  ↔  (  ⊥  ‘ (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  =  ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) ) | 
						
							| 36 | 32 35 | mpbid | ⊢ ( 𝜑  →  (  ⊥  ‘ (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  =  ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) | 
						
							| 37 | 17 18 19 1 29 20 21 30 36 | dochexmid | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊕  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  =  𝑉 ) | 
						
							| 38 | 17 19 21 | dvhlvec | ⊢ ( 𝜑  →  𝑈  ∈  LVec ) | 
						
							| 39 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 38 24 25 | lclkrlem2n | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) | 
						
							| 40 | 11 | snssd | ⊢ ( 𝜑  →  { 𝑋 }  ⊆  𝑉 ) | 
						
							| 41 | 12 | snssd | ⊢ ( 𝜑  →  { 𝑌 }  ⊆  𝑉 ) | 
						
							| 42 | 17 19 1 18 | dochdmj1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  { 𝑋 }  ⊆  𝑉  ∧  { 𝑌 }  ⊆  𝑉 )  →  (  ⊥  ‘ ( { 𝑋 }  ∪  { 𝑌 } ) )  =  ( (  ⊥  ‘ { 𝑋 } )  ∩  (  ⊥  ‘ { 𝑌 } ) ) ) | 
						
							| 43 | 21 40 41 42 | syl3anc | ⊢ ( 𝜑  →  (  ⊥  ‘ ( { 𝑋 }  ∪  { 𝑌 } ) )  =  ( (  ⊥  ‘ { 𝑋 } )  ∩  (  ⊥  ‘ { 𝑌 } ) ) ) | 
						
							| 44 |  | df-pr | ⊢ { 𝑋 ,  𝑌 }  =  ( { 𝑋 }  ∪  { 𝑌 } ) | 
						
							| 45 | 44 | fveq2i | ⊢ ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  =  ( 𝑁 ‘ ( { 𝑋 }  ∪  { 𝑌 } ) ) | 
						
							| 46 | 45 | fveq2i | ⊢ (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  =  (  ⊥  ‘ ( 𝑁 ‘ ( { 𝑋 }  ∪  { 𝑌 } ) ) ) | 
						
							| 47 | 40 41 | unssd | ⊢ ( 𝜑  →  ( { 𝑋 }  ∪  { 𝑌 } )  ⊆  𝑉 ) | 
						
							| 48 | 17 19 18 1 15 21 47 | dochocsp | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ ( { 𝑋 }  ∪  { 𝑌 } ) ) )  =  (  ⊥  ‘ ( { 𝑋 }  ∪  { 𝑌 } ) ) ) | 
						
							| 49 | 46 48 | eqtrid | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  =  (  ⊥  ‘ ( { 𝑋 }  ∪  { 𝑌 } ) ) ) | 
						
							| 50 | 22 23 | ineq12d | ⊢ ( 𝜑  →  ( ( 𝐿 ‘ 𝐸 )  ∩  ( 𝐿 ‘ 𝐺 ) )  =  ( (  ⊥  ‘ { 𝑋 } )  ∩  (  ⊥  ‘ { 𝑌 } ) ) ) | 
						
							| 51 | 43 49 50 | 3eqtr4d | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  =  ( ( 𝐿 ‘ 𝐸 )  ∩  ( 𝐿 ‘ 𝐺 ) ) ) | 
						
							| 52 | 8 16 9 10 26 13 14 | lkrin | ⊢ ( 𝜑  →  ( ( 𝐿 ‘ 𝐸 )  ∩  ( 𝐿 ‘ 𝐺 ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) | 
						
							| 53 | 51 52 | eqsstrd | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) | 
						
							| 54 | 29 | lsssssubg | ⊢ ( 𝑈  ∈  LMod  →  ( LSubSp ‘ 𝑈 )  ⊆  ( SubGrp ‘ 𝑈 ) ) | 
						
							| 55 | 26 54 | syl | ⊢ ( 𝜑  →  ( LSubSp ‘ 𝑈 )  ⊆  ( SubGrp ‘ 𝑈 ) ) | 
						
							| 56 | 55 30 | sseldd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ( SubGrp ‘ 𝑈 ) ) | 
						
							| 57 | 17 19 1 29 18 | dochlss | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  𝑉 )  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 58 | 21 34 57 | syl2anc | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 59 | 55 58 | sseldd | ⊢ ( 𝜑  →  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ∈  ( SubGrp ‘ 𝑈 ) ) | 
						
							| 60 | 8 16 29 | lkrlss | ⊢ ( ( 𝑈  ∈  LMod  ∧  ( 𝐸  +  𝐺 )  ∈  𝐹 )  →  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 61 | 26 27 60 | syl2anc | ⊢ ( 𝜑  →  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∈  ( LSubSp ‘ 𝑈 ) ) | 
						
							| 62 | 55 61 | sseldd | ⊢ ( 𝜑  →  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∈  ( SubGrp ‘ 𝑈 ) ) | 
						
							| 63 | 20 | lsmlub | ⊢ ( ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ∈  ( SubGrp ‘ 𝑈 )  ∧  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ∈  ( SubGrp ‘ 𝑈 )  ∧  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∈  ( SubGrp ‘ 𝑈 ) )  →  ( ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∧  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) )  ↔  ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊕  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) ) | 
						
							| 64 | 56 59 62 63 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  ∧  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) )  ↔  ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊕  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) ) | 
						
							| 65 | 39 53 64 | mpbi2and | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 ,  𝑌 } )  ⊕  (  ⊥  ‘ ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) )  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) | 
						
							| 66 | 37 65 | eqsstrrd | ⊢ ( 𝜑  →  𝑉  ⊆  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) ) ) | 
						
							| 67 | 28 66 | eqssd | ⊢ ( 𝜑  →  ( 𝐿 ‘ ( 𝐸  +  𝐺 ) )  =  𝑉 ) |