| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdval.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | mapdval.u | ⊢ 𝑈  =  ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | mapdval.s | ⊢ 𝑆  =  ( LSubSp ‘ 𝑈 ) | 
						
							| 4 |  | mapdval.f | ⊢ 𝐹  =  ( LFnl ‘ 𝑈 ) | 
						
							| 5 |  | mapdval.l | ⊢ 𝐿  =  ( LKer ‘ 𝑈 ) | 
						
							| 6 |  | mapdval.o | ⊢ 𝑂  =  ( ( ocH ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 7 |  | mapdval.m | ⊢ 𝑀  =  ( ( mapd ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 |  | mapdval.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  𝑋  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 9 |  | mapdval.t | ⊢ ( 𝜑  →  𝑇  ∈  𝑆 ) | 
						
							| 10 |  | mapdvalc.c | ⊢ 𝐶  =  { 𝑔  ∈  𝐹  ∣  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑔 ) ) )  =  ( 𝐿 ‘ 𝑔 ) } | 
						
							| 11 | 1 2 3 4 5 6 7 8 9 | mapdval | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝑇 )  =  { 𝑓  ∈  𝐹  ∣  ( ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) } ) | 
						
							| 12 |  | anass | ⊢ ( ( ( 𝑓  ∈  𝐹  ∧  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 ) )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 )  ↔  ( 𝑓  ∈  𝐹  ∧  ( ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) ) ) | 
						
							| 13 | 10 | lcfl1lem | ⊢ ( 𝑓  ∈  𝐶  ↔  ( 𝑓  ∈  𝐹  ∧  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 ) ) ) | 
						
							| 14 | 13 | anbi1i | ⊢ ( ( 𝑓  ∈  𝐶  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 )  ↔  ( ( 𝑓  ∈  𝐹  ∧  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 ) )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) ) | 
						
							| 15 | 14 | bicomi | ⊢ ( ( ( 𝑓  ∈  𝐹  ∧  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 ) )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 )  ↔  ( 𝑓  ∈  𝐶  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) ) | 
						
							| 16 | 15 | a1i | ⊢ ( 𝜑  →  ( ( ( 𝑓  ∈  𝐹  ∧  ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 ) )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 )  ↔  ( 𝑓  ∈  𝐶  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) ) ) | 
						
							| 17 | 12 16 | bitr3id | ⊢ ( 𝜑  →  ( ( 𝑓  ∈  𝐹  ∧  ( ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) )  ↔  ( 𝑓  ∈  𝐶  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) ) ) | 
						
							| 18 | 17 | rabbidva2 | ⊢ ( 𝜑  →  { 𝑓  ∈  𝐹  ∣  ( ( 𝑂 ‘ ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) ) )  =  ( 𝐿 ‘ 𝑓 )  ∧  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 ) }  =  { 𝑓  ∈  𝐶  ∣  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 } ) | 
						
							| 19 | 11 18 | eqtrd | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝑇 )  =  { 𝑓  ∈  𝐶  ∣  ( 𝑂 ‘ ( 𝐿 ‘ 𝑓 ) )  ⊆  𝑇 } ) |