| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvhvaddcl.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | dvhvaddcl.t | ⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | dvhvaddcl.e | ⊢ 𝐸  =  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 4 |  | dvhvaddcl.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 5 |  | dvhvaddcl.d | ⊢ 𝐷  =  ( Scalar ‘ 𝑈 ) | 
						
							| 6 |  | dvhvaddcl.p | ⊢  ⨣   =  ( +g ‘ 𝐷 ) | 
						
							| 7 |  | dvhvaddcl.a | ⊢  +   =  ( +g ‘ 𝑈 ) | 
						
							| 8 |  | coass | ⊢ ( ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) )  =  ( ( 1st  ‘ 𝐹 )  ∘  ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ) | 
						
							| 9 | 1 2 3 4 5 7 6 | dvhvadd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  𝐺 )  =  〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 ) | 
						
							| 10 | 9 | 3adantr3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  𝐺 )  =  〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 ) | 
						
							| 11 | 10 | fveq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 1st  ‘ ( 𝐹  +  𝐺 ) )  =  ( 1st  ‘ 〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 ) ) | 
						
							| 12 |  | fvex | ⊢ ( 1st  ‘ 𝐹 )  ∈  V | 
						
							| 13 |  | fvex | ⊢ ( 1st  ‘ 𝐺 )  ∈  V | 
						
							| 14 | 12 13 | coex | ⊢ ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) )  ∈  V | 
						
							| 15 |  | ovex | ⊢ ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) )  ∈  V | 
						
							| 16 | 14 15 | op1st | ⊢ ( 1st  ‘ 〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 )  =  ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) | 
						
							| 17 | 11 16 | eqtrdi | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 1st  ‘ ( 𝐹  +  𝐺 ) )  =  ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ) | 
						
							| 18 | 17 | coeq1d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 1st  ‘ ( 𝐹  +  𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) )  =  ( ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) ) ) | 
						
							| 19 | 1 2 3 4 5 7 6 | dvhvadd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐺  +  𝐼 )  =  〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) | 
						
							| 20 | 19 | 3adantr1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐺  +  𝐼 )  =  〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) | 
						
							| 21 | 20 | fveq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 1st  ‘ ( 𝐺  +  𝐼 ) )  =  ( 1st  ‘ 〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) ) | 
						
							| 22 |  | fvex | ⊢ ( 1st  ‘ 𝐼 )  ∈  V | 
						
							| 23 | 13 22 | coex | ⊢ ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) )  ∈  V | 
						
							| 24 |  | ovex | ⊢ ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) )  ∈  V | 
						
							| 25 | 23 24 | op1st | ⊢ ( 1st  ‘ 〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 )  =  ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) | 
						
							| 26 | 21 25 | eqtrdi | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 1st  ‘ ( 𝐺  +  𝐼 ) )  =  ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ) | 
						
							| 27 | 26 | coeq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ ( 𝐺  +  𝐼 ) ) )  =  ( ( 1st  ‘ 𝐹 )  ∘  ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ) ) | 
						
							| 28 | 8 18 27 | 3eqtr4a | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 1st  ‘ ( 𝐹  +  𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) )  =  ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ ( 𝐺  +  𝐼 ) ) ) ) | 
						
							| 29 |  | xp2nd | ⊢ ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  →  ( 2nd  ‘ 𝐹 )  ∈  𝐸 ) | 
						
							| 30 |  | xp2nd | ⊢ ( 𝐺  ∈  ( 𝑇  ×  𝐸 )  →  ( 2nd  ‘ 𝐺 )  ∈  𝐸 ) | 
						
							| 31 |  | xp2nd | ⊢ ( 𝐼  ∈  ( 𝑇  ×  𝐸 )  →  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) | 
						
							| 32 | 29 30 31 | 3anim123i | ⊢ ( ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) )  →  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) ) | 
						
							| 33 |  | eqid | ⊢ ( ( EDRing ‘ 𝐾 ) ‘ 𝑊 )  =  ( ( EDRing ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 34 | 1 33 4 5 | dvhsca | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  →  𝐷  =  ( ( EDRing ‘ 𝐾 ) ‘ 𝑊 ) ) | 
						
							| 35 | 1 33 | erngdv | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  →  ( ( EDRing ‘ 𝐾 ) ‘ 𝑊 )  ∈  DivRing ) | 
						
							| 36 | 34 35 | eqeltrd | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  →  𝐷  ∈  DivRing ) | 
						
							| 37 |  | drnggrp | ⊢ ( 𝐷  ∈  DivRing  →  𝐷  ∈  Grp ) | 
						
							| 38 | 36 37 | syl | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  →  𝐷  ∈  Grp ) | 
						
							| 39 | 38 | adantr | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  𝐷  ∈  Grp ) | 
						
							| 40 |  | simpr1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐹 )  ∈  𝐸 ) | 
						
							| 41 |  | eqid | ⊢ ( Base ‘ 𝐷 )  =  ( Base ‘ 𝐷 ) | 
						
							| 42 | 1 3 4 5 41 | dvhbase | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  →  ( Base ‘ 𝐷 )  =  𝐸 ) | 
						
							| 43 | 42 | adantr | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( Base ‘ 𝐷 )  =  𝐸 ) | 
						
							| 44 | 40 43 | eleqtrrd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐹 )  ∈  ( Base ‘ 𝐷 ) ) | 
						
							| 45 |  | simpr2 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐺 )  ∈  𝐸 ) | 
						
							| 46 | 45 43 | eleqtrrd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐺 )  ∈  ( Base ‘ 𝐷 ) ) | 
						
							| 47 |  | simpr3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) | 
						
							| 48 | 47 43 | eleqtrrd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( 2nd  ‘ 𝐼 )  ∈  ( Base ‘ 𝐷 ) ) | 
						
							| 49 | 41 6 | grpass | ⊢ ( ( 𝐷  ∈  Grp  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  ( Base ‘ 𝐷 )  ∧  ( 2nd  ‘ 𝐺 )  ∈  ( Base ‘ 𝐷 )  ∧  ( 2nd  ‘ 𝐼 )  ∈  ( Base ‘ 𝐷 ) ) )  →  ( ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) ) | 
						
							| 50 | 39 44 46 48 49 | syl13anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 2nd  ‘ 𝐹 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐺 )  ∈  𝐸  ∧  ( 2nd  ‘ 𝐼 )  ∈  𝐸 ) )  →  ( ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) ) | 
						
							| 51 | 32 50 | sylan2 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) ) | 
						
							| 52 | 10 | fveq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  =  ( 2nd  ‘ 〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 ) ) | 
						
							| 53 | 14 15 | op2nd | ⊢ ( 2nd  ‘ 〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ 𝐺 ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) 〉 )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) | 
						
							| 54 | 52 53 | eqtrdi | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) ) ) | 
						
							| 55 | 54 | oveq1d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) )  =  ( ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ 𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) | 
						
							| 56 | 20 | fveq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 2nd  ‘ ( 𝐺  +  𝐼 ) )  =  ( 2nd  ‘ 〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) ) | 
						
							| 57 | 23 24 | op2nd | ⊢ ( 2nd  ‘ 〈 ( ( 1st  ‘ 𝐺 )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 )  =  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) | 
						
							| 58 | 56 57 | eqtrdi | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 2nd  ‘ ( 𝐺  +  𝐼 ) )  =  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) | 
						
							| 59 | 58 | oveq2d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ ( 𝐺  +  𝐼 ) ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( ( 2nd  ‘ 𝐺 )  ⨣  ( 2nd  ‘ 𝐼 ) ) ) ) | 
						
							| 60 | 51 55 59 | 3eqtr4d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) )  =  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ ( 𝐺  +  𝐼 ) ) ) ) | 
						
							| 61 | 28 60 | opeq12d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  〈 ( ( 1st  ‘ ( 𝐹  +  𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉  =  〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ ( 𝐺  +  𝐼 ) ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ ( 𝐺  +  𝐼 ) ) ) 〉 ) | 
						
							| 62 |  | simpl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 63 | 1 2 3 4 5 6 7 | dvhvaddcl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  𝐺 )  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 64 | 63 | 3adantr3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  𝐺 )  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 65 |  | simpr3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 66 | 1 2 3 4 5 7 6 | dvhvadd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( ( 𝐹  +  𝐺 )  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 𝐹  +  𝐺 )  +  𝐼 )  =  〈 ( ( 1st  ‘ ( 𝐹  +  𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) | 
						
							| 67 | 62 64 65 66 | syl12anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 𝐹  +  𝐺 )  +  𝐼 )  =  〈 ( ( 1st  ‘ ( 𝐹  +  𝐺 ) )  ∘  ( 1st  ‘ 𝐼 ) ) ,  ( ( 2nd  ‘ ( 𝐹  +  𝐺 ) )  ⨣  ( 2nd  ‘ 𝐼 ) ) 〉 ) | 
						
							| 68 |  | simpr1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  𝐹  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 69 | 1 2 3 4 5 6 7 | dvhvaddcl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐺  +  𝐼 )  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 70 | 69 | 3adantr1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐺  +  𝐼 )  ∈  ( 𝑇  ×  𝐸 ) ) | 
						
							| 71 | 1 2 3 4 5 7 6 | dvhvadd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  ( 𝐺  +  𝐼 )  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  ( 𝐺  +  𝐼 ) )  =  〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ ( 𝐺  +  𝐼 ) ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ ( 𝐺  +  𝐼 ) ) ) 〉 ) | 
						
							| 72 | 62 68 70 71 | syl12anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( 𝐹  +  ( 𝐺  +  𝐼 ) )  =  〈 ( ( 1st  ‘ 𝐹 )  ∘  ( 1st  ‘ ( 𝐺  +  𝐼 ) ) ) ,  ( ( 2nd  ‘ 𝐹 )  ⨣  ( 2nd  ‘ ( 𝐺  +  𝐼 ) ) ) 〉 ) | 
						
							| 73 | 61 67 72 | 3eqtr4d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐺  ∈  ( 𝑇  ×  𝐸 )  ∧  𝐼  ∈  ( 𝑇  ×  𝐸 ) ) )  →  ( ( 𝐹  +  𝐺 )  +  𝐼 )  =  ( 𝐹  +  ( 𝐺  +  𝐼 ) ) ) |