| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdindp1.v | ⊢ 𝑉  =  ( Base ‘ 𝑊 ) | 
						
							| 2 |  | mapdindp1.p | ⊢  +   =  ( +g ‘ 𝑊 ) | 
						
							| 3 |  | mapdindp1.o | ⊢  0   =  ( 0g ‘ 𝑊 ) | 
						
							| 4 |  | mapdindp1.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑊 ) | 
						
							| 5 |  | mapdindp1.w | ⊢ ( 𝜑  →  𝑊  ∈  LVec ) | 
						
							| 6 |  | mapdindp1.x | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 7 |  | mapdindp1.y | ⊢ ( 𝜑  →  𝑌  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 8 |  | mapdindp1.z | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 9 |  | mapdindp1.W | ⊢ ( 𝜑  →  𝑤  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 10 |  | mapdindp1.e | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  =  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 11 |  | mapdindp1.ne | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 12 |  | mapdindp1.f | ⊢ ( 𝜑  →  ¬  𝑤  ∈  ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) | 
						
							| 13 |  | lveclmod | ⊢ ( 𝑊  ∈  LVec  →  𝑊  ∈  LMod ) | 
						
							| 14 | 5 13 | syl | ⊢ ( 𝜑  →  𝑊  ∈  LMod ) | 
						
							| 15 | 9 | eldifad | ⊢ ( 𝜑  →  𝑤  ∈  𝑉 ) | 
						
							| 16 | 7 | eldifad | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 17 | 1 2 4 | lspvadd | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑤  ∈  𝑉  ∧  𝑌  ∈  𝑉 )  →  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } )  ⊆  ( 𝑁 ‘ { 𝑤 ,  𝑌 } ) ) | 
						
							| 18 | 14 15 16 17 | syl3anc | ⊢ ( 𝜑  →  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } )  ⊆  ( 𝑁 ‘ { 𝑤 ,  𝑌 } ) ) | 
						
							| 19 | 1 3 4 5 6 16 15 11 12 | lspindp1 | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑤 } )  ≠  ( 𝑁 ‘ { 𝑌 } )  ∧  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑤 ,  𝑌 } ) ) ) | 
						
							| 20 | 19 | simprd | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { 𝑤 ,  𝑌 } ) ) | 
						
							| 21 | 18 20 | ssneldd | ⊢ ( 𝜑  →  ¬  𝑋  ∈  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } ) ) | 
						
							| 22 | 6 | eldifad | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 23 | 1 4 | lspsnid | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑋  ∈  𝑉 )  →  𝑋  ∈  ( 𝑁 ‘ { 𝑋 } ) ) | 
						
							| 24 | 14 22 23 | syl2anc | ⊢ ( 𝜑  →  𝑋  ∈  ( 𝑁 ‘ { 𝑋 } ) ) | 
						
							| 25 |  | eleq2 | ⊢ ( ( 𝑁 ‘ { 𝑋 } )  =  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } )  →  ( 𝑋  ∈  ( 𝑁 ‘ { 𝑋 } )  ↔  𝑋  ∈  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } ) ) ) | 
						
							| 26 | 24 25 | syl5ibcom | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  =  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } )  →  𝑋  ∈  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } ) ) ) | 
						
							| 27 | 26 | necon3bd | ⊢ ( 𝜑  →  ( ¬  𝑋  ∈  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } )  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } ) ) ) | 
						
							| 28 | 21 27 | mpd | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { ( 𝑤  +  𝑌 ) } ) ) |