| Step | Hyp | Ref | Expression | 
						
							| 1 |  | hdmapellkr.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | hdmapellkr.o | ⊢ 𝑂  =  ( ( ocH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | hdmapellkr.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 4 |  | hdmapellkr.v | ⊢ 𝑉  =  ( Base ‘ 𝑈 ) | 
						
							| 5 |  | hdmapellkr.r | ⊢ 𝑅  =  ( Scalar ‘ 𝑈 ) | 
						
							| 6 |  | hdmapellkr.z | ⊢  0   =  ( 0g ‘ 𝑅 ) | 
						
							| 7 |  | hdmapellkr.s | ⊢ 𝑆  =  ( ( HDMap ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 |  | hdmapellkr.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 9 |  | hdmapellkr.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 10 |  | hdmapellkr.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 11 |  | eqid | ⊢ ( LFnl ‘ 𝑈 )  =  ( LFnl ‘ 𝑈 ) | 
						
							| 12 |  | eqid | ⊢ ( LKer ‘ 𝑈 )  =  ( LKer ‘ 𝑈 ) | 
						
							| 13 | 1 3 8 | dvhlmod | ⊢ ( 𝜑  →  𝑈  ∈  LMod ) | 
						
							| 14 |  | eqid | ⊢ ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 )  =  ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 15 |  | eqid | ⊢ ( Base ‘ ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) )  =  ( Base ‘ ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) ) | 
						
							| 16 | 1 3 4 14 15 7 8 9 | hdmapcl | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝑋 )  ∈  ( Base ‘ ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 ) ) ) | 
						
							| 17 | 1 14 15 3 11 8 16 | lcdvbaselfl | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝑋 )  ∈  ( LFnl ‘ 𝑈 ) ) | 
						
							| 18 | 4 5 6 11 12 13 17 10 | ellkr2 | ⊢ ( 𝜑  →  ( 𝑌  ∈  ( ( LKer ‘ 𝑈 ) ‘ ( 𝑆 ‘ 𝑋 ) )  ↔  ( ( 𝑆 ‘ 𝑋 ) ‘ 𝑌 )  =   0  ) ) | 
						
							| 19 | 1 2 3 4 11 12 7 8 9 | hdmaplkr | ⊢ ( 𝜑  →  ( ( LKer ‘ 𝑈 ) ‘ ( 𝑆 ‘ 𝑋 ) )  =  ( 𝑂 ‘ { 𝑋 } ) ) | 
						
							| 20 | 19 | eleq2d | ⊢ ( 𝜑  →  ( 𝑌  ∈  ( ( LKer ‘ 𝑈 ) ‘ ( 𝑆 ‘ 𝑋 ) )  ↔  𝑌  ∈  ( 𝑂 ‘ { 𝑋 } ) ) ) | 
						
							| 21 | 18 20 | bitr3d | ⊢ ( 𝜑  →  ( ( ( 𝑆 ‘ 𝑋 ) ‘ 𝑌 )  =   0   ↔  𝑌  ∈  ( 𝑂 ‘ { 𝑋 } ) ) ) |