| Step | Hyp | Ref | Expression | 
						
							| 1 |  | baerlem3.v | ⊢ 𝑉  =  ( Base ‘ 𝑊 ) | 
						
							| 2 |  | baerlem3.m | ⊢  −   =  ( -g ‘ 𝑊 ) | 
						
							| 3 |  | baerlem3.o | ⊢  0   =  ( 0g ‘ 𝑊 ) | 
						
							| 4 |  | baerlem3.s | ⊢  ⊕   =  ( LSSum ‘ 𝑊 ) | 
						
							| 5 |  | baerlem3.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑊 ) | 
						
							| 6 |  | baerlem3.w | ⊢ ( 𝜑  →  𝑊  ∈  LVec ) | 
						
							| 7 |  | baerlem3.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 8 |  | baerlem3.c | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑍 } ) ) | 
						
							| 9 |  | baerlem3.d | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 10 |  | baerlem3.y | ⊢ ( 𝜑  →  𝑌  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 11 |  | baerlem3.z | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 12 |  | baerlem5a.p | ⊢  +   =  ( +g ‘ 𝑊 ) | 
						
							| 13 | 10 | eldifad | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 14 | 11 | eldifad | ⊢ ( 𝜑  →  𝑍  ∈  𝑉 ) | 
						
							| 15 |  | eqid | ⊢ ( invg ‘ 𝑊 )  =  ( invg ‘ 𝑊 ) | 
						
							| 16 | 1 12 15 2 | grpsubval | ⊢ ( ( 𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑉 )  →  ( 𝑌  −  𝑍 )  =  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) | 
						
							| 17 | 13 14 16 | syl2anc | ⊢ ( 𝜑  →  ( 𝑌  −  𝑍 )  =  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) | 
						
							| 18 | 17 | sneqd | ⊢ ( 𝜑  →  { ( 𝑌  −  𝑍 ) }  =  { ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) } ) | 
						
							| 19 | 18 | fveq2d | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑌  −  𝑍 ) } )  =  ( 𝑁 ‘ { ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) } ) ) | 
						
							| 20 |  | lveclmod | ⊢ ( 𝑊  ∈  LVec  →  𝑊  ∈  LMod ) | 
						
							| 21 | 6 20 | syl | ⊢ ( 𝜑  →  𝑊  ∈  LMod ) | 
						
							| 22 | 1 15 | lmodvnegcl | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑍  ∈  𝑉 )  →  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  𝑉 ) | 
						
							| 23 | 21 14 22 | syl2anc | ⊢ ( 𝜑  →  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  𝑉 ) | 
						
							| 24 |  | eqid | ⊢ ( LSubSp ‘ 𝑊 )  =  ( LSubSp ‘ 𝑊 ) | 
						
							| 25 | 1 24 5 21 13 14 | lspprcl | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 ,  𝑍 } )  ∈  ( LSubSp ‘ 𝑊 ) ) | 
						
							| 26 | 3 24 21 25 7 8 | lssneln0 | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 27 | 1 5 6 7 13 14 8 | lspindpi | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } )  ∧  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑍 } ) ) ) | 
						
							| 28 | 27 | simpld | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 29 | 1 3 5 6 26 13 28 | lspsnne1 | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 30 | 9 | necomd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑍 } )  ≠  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 31 | 1 3 5 6 11 13 30 | lspsnne1 | ⊢ ( 𝜑  →  ¬  𝑍  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 32 | 1 5 6 7 14 13 31 8 | lspexchn2 | ⊢ ( 𝜑  →  ¬  𝑍  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 33 |  | lmodgrp | ⊢ ( 𝑊  ∈  LMod  →  𝑊  ∈  Grp ) | 
						
							| 34 | 21 33 | syl | ⊢ ( 𝜑  →  𝑊  ∈  Grp ) | 
						
							| 35 | 34 | adantr | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  𝑊  ∈  Grp ) | 
						
							| 36 | 14 | adantr | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  𝑍  ∈  𝑉 ) | 
						
							| 37 | 1 15 | grpinvinv | ⊢ ( ( 𝑊  ∈  Grp  ∧  𝑍  ∈  𝑉 )  →  ( ( invg ‘ 𝑊 ) ‘ ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) )  =  𝑍 ) | 
						
							| 38 | 35 36 37 | syl2anc | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  ( ( invg ‘ 𝑊 ) ‘ ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) )  =  𝑍 ) | 
						
							| 39 | 21 | adantr | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  𝑊  ∈  LMod ) | 
						
							| 40 | 1 24 5 21 13 7 | lspprcl | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 ,  𝑋 } )  ∈  ( LSubSp ‘ 𝑊 ) ) | 
						
							| 41 | 40 | adantr | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  ( 𝑁 ‘ { 𝑌 ,  𝑋 } )  ∈  ( LSubSp ‘ 𝑊 ) ) | 
						
							| 42 |  | simpr | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 43 | 24 15 | lssvnegcl | ⊢ ( ( 𝑊  ∈  LMod  ∧  ( 𝑁 ‘ { 𝑌 ,  𝑋 } )  ∈  ( LSubSp ‘ 𝑊 )  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  ( ( invg ‘ 𝑊 ) ‘ ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 44 | 39 41 42 43 | syl3anc | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  ( ( invg ‘ 𝑊 ) ‘ ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 45 | 38 44 | eqeltrrd | ⊢ ( ( 𝜑  ∧  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) )  →  𝑍  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 46 | 32 45 | mtand | ⊢ ( 𝜑  →  ¬  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑁 ‘ { 𝑌 ,  𝑋 } ) ) | 
						
							| 47 | 1 5 6 23 7 13 29 46 | lspexchn2 | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑌 ,  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } ) ) | 
						
							| 48 | 1 15 5 | lspsnneg | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑍  ∈  𝑉 )  →  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } )  =  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 49 | 21 14 48 | syl2anc | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } )  =  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 50 | 9 49 | neeqtrrd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  ≠  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } ) ) | 
						
							| 51 | 1 3 15 | grpinvnzcl | ⊢ ( ( 𝑊  ∈  Grp  ∧  𝑍  ∈  ( 𝑉  ∖  {  0  } ) )  →  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 52 | 34 11 51 | syl2anc | ⊢ ( 𝜑  →  ( ( invg ‘ 𝑊 ) ‘ 𝑍 )  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 53 | 1 2 3 4 5 6 7 47 50 10 52 12 | baerlem5b | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) } )  =  ( ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } ) )  ∩  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) ) ) ) | 
						
							| 54 | 49 | oveq2d | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } ) )  =  ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { 𝑍 } ) ) ) | 
						
							| 55 | 17 | eqcomd | ⊢ ( 𝜑  →  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) )  =  ( 𝑌  −  𝑍 ) ) | 
						
							| 56 | 55 | oveq2d | ⊢ ( 𝜑  →  ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) )  =  ( 𝑋  −  ( 𝑌  −  𝑍 ) ) ) | 
						
							| 57 | 56 | sneqd | ⊢ ( 𝜑  →  { ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) }  =  { ( 𝑋  −  ( 𝑌  −  𝑍 ) ) } ) | 
						
							| 58 | 57 | fveq2d | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) } )  =  ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  −  𝑍 ) ) } ) ) | 
						
							| 59 | 58 | oveq1d | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) )  =  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  −  𝑍 ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) ) ) | 
						
							| 60 | 54 59 | ineq12d | ⊢ ( 𝜑  →  ( ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) } ) )  ∩  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  +  ( ( invg ‘ 𝑊 ) ‘ 𝑍 ) ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) ) )  =  ( ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { 𝑍 } ) )  ∩  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  −  𝑍 ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) ) ) ) | 
						
							| 61 | 19 53 60 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑌  −  𝑍 ) } )  =  ( ( ( 𝑁 ‘ { 𝑌 } )  ⊕  ( 𝑁 ‘ { 𝑍 } ) )  ∩  ( ( 𝑁 ‘ { ( 𝑋  −  ( 𝑌  −  𝑍 ) ) } )  ⊕  ( 𝑁 ‘ { 𝑋 } ) ) ) ) |