| 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 |  | eldifsni | ⊢ ( 𝑋  ∈  ( 𝑉  ∖  {  0  } )  →  𝑋  ≠   0  ) | 
						
							| 14 | 6 13 | syl | ⊢ ( 𝜑  →  𝑋  ≠   0  ) | 
						
							| 15 |  | lveclmod | ⊢ ( 𝑊  ∈  LVec  →  𝑊  ∈  LMod ) | 
						
							| 16 | 5 15 | syl | ⊢ ( 𝜑  →  𝑊  ∈  LMod ) | 
						
							| 17 | 3 4 | lspsn0 | ⊢ ( 𝑊  ∈  LMod  →  ( 𝑁 ‘ {  0  } )  =  {  0  } ) | 
						
							| 18 | 16 17 | syl | ⊢ ( 𝜑  →  ( 𝑁 ‘ {  0  } )  =  {  0  } ) | 
						
							| 19 | 18 | eqeq2d | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  =  ( 𝑁 ‘ {  0  } )  ↔  ( 𝑁 ‘ { 𝑋 } )  =  {  0  } ) ) | 
						
							| 20 | 6 | eldifad | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 21 | 1 3 4 | lspsneq0 | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑋  ∈  𝑉 )  →  ( ( 𝑁 ‘ { 𝑋 } )  =  {  0  }  ↔  𝑋  =   0  ) ) | 
						
							| 22 | 16 20 21 | syl2anc | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  =  {  0  }  ↔  𝑋  =   0  ) ) | 
						
							| 23 | 19 22 | bitrd | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  =  ( 𝑁 ‘ {  0  } )  ↔  𝑋  =   0  ) ) | 
						
							| 24 | 23 | necon3bid | ⊢ ( 𝜑  →  ( ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ {  0  } )  ↔  𝑋  ≠   0  ) ) | 
						
							| 25 | 14 24 | mpbird | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ {  0  } ) ) | 
						
							| 26 | 25 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  =   0  )  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ {  0  } ) ) | 
						
							| 27 |  | sneq | ⊢ ( ( 𝑌  +  𝑍 )  =   0   →  { ( 𝑌  +  𝑍 ) }  =  {  0  } ) | 
						
							| 28 | 27 | fveq2d | ⊢ ( ( 𝑌  +  𝑍 )  =   0   →  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } )  =  ( 𝑁 ‘ {  0  } ) ) | 
						
							| 29 | 28 | adantl | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  =   0  )  →  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } )  =  ( 𝑁 ‘ {  0  } ) ) | 
						
							| 30 | 26 29 | neeqtrrd | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  =   0  )  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } ) ) | 
						
							| 31 | 11 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 32 | 5 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  𝑊  ∈  LVec ) | 
						
							| 33 | 6 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  𝑋  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 34 | 7 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  𝑌  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 35 | 8 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 36 | 9 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  𝑤  ∈  ( 𝑉  ∖  {  0  } ) ) | 
						
							| 37 | 10 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ( 𝑁 ‘ { 𝑌 } )  =  ( 𝑁 ‘ { 𝑍 } ) ) | 
						
							| 38 | 12 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ¬  𝑤  ∈  ( 𝑁 ‘ { 𝑋 ,  𝑌 } ) ) | 
						
							| 39 |  | simpr | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ( 𝑌  +  𝑍 )  ≠   0  ) | 
						
							| 40 | 1 2 3 4 32 33 34 35 36 37 31 38 39 | mapdindp0 | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } )  =  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 41 | 31 40 | neeqtrrd | ⊢ ( ( 𝜑  ∧  ( 𝑌  +  𝑍 )  ≠   0  )  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } ) ) | 
						
							| 42 | 30 41 | pm2.61dane | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑋 } )  ≠  ( 𝑁 ‘ { ( 𝑌  +  𝑍 ) } ) ) |