| Step | Hyp | Ref | Expression | 
						
							| 1 |  | hdmaplem1.v | ⊢ 𝑉  =  ( Base ‘ 𝑊 ) | 
						
							| 2 |  | hdmaplem1.n | ⊢ 𝑁  =  ( LSpan ‘ 𝑊 ) | 
						
							| 3 |  | hdmaplem1.w | ⊢ ( 𝜑  →  𝑊  ∈  LMod ) | 
						
							| 4 |  | hdmaplem1.z | ⊢ ( 𝜑  →  𝑍  ∈  𝑉 ) | 
						
							| 5 |  | hdmaplem1.j | ⊢ ( 𝜑  →  ¬  𝑍  ∈  ( ( 𝑁 ‘ { 𝑋 } )  ∪  ( 𝑁 ‘ { 𝑌 } ) ) ) | 
						
							| 6 |  | hdmaplem1.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 7 |  | hdmaplem3.o | ⊢  0   =  ( 0g ‘ 𝑊 ) | 
						
							| 8 |  | eqid | ⊢ ( LSubSp ‘ 𝑊 )  =  ( LSubSp ‘ 𝑊 ) | 
						
							| 9 | 1 8 2 | lspsncl | ⊢ ( ( 𝑊  ∈  LMod  ∧  𝑌  ∈  𝑉 )  →  ( 𝑁 ‘ { 𝑌 } )  ∈  ( LSubSp ‘ 𝑊 ) ) | 
						
							| 10 | 3 6 9 | syl2anc | ⊢ ( 𝜑  →  ( 𝑁 ‘ { 𝑌 } )  ∈  ( LSubSp ‘ 𝑊 ) ) | 
						
							| 11 |  | elun2 | ⊢ ( 𝑍  ∈  ( 𝑁 ‘ { 𝑌 } )  →  𝑍  ∈  ( ( 𝑁 ‘ { 𝑋 } )  ∪  ( 𝑁 ‘ { 𝑌 } ) ) ) | 
						
							| 12 | 5 11 | nsyl | ⊢ ( 𝜑  →  ¬  𝑍  ∈  ( 𝑁 ‘ { 𝑌 } ) ) | 
						
							| 13 | 7 8 3 10 4 12 | lssneln0 | ⊢ ( 𝜑  →  𝑍  ∈  ( 𝑉  ∖  {  0  } ) ) |