| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pjfval2.o | ⊢  ⊥   =  ( ocv ‘ 𝑊 ) | 
						
							| 2 |  | pjfval2.p | ⊢ 𝑃  =  ( proj1 ‘ 𝑊 ) | 
						
							| 3 |  | pjfval2.k | ⊢ 𝐾  =  ( proj ‘ 𝑊 ) | 
						
							| 4 |  | df-mpt | ⊢ ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) } | 
						
							| 5 |  | df-xp | ⊢ ( V  ×  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) )  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) } | 
						
							| 6 | 4 5 | ineq12i | ⊢ ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∩  ( V  ×  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) )  =  ( { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) }  ∩  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) } ) | 
						
							| 7 |  | eqid | ⊢ ( Base ‘ 𝑊 )  =  ( Base ‘ 𝑊 ) | 
						
							| 8 |  | eqid | ⊢ ( LSubSp ‘ 𝑊 )  =  ( LSubSp ‘ 𝑊 ) | 
						
							| 9 | 7 8 1 2 3 | pjfval | ⊢ 𝐾  =  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∩  ( V  ×  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) | 
						
							| 10 | 7 8 1 2 3 | pjdm | ⊢ ( 𝑥  ∈  dom  𝐾  ↔  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) : ( Base ‘ 𝑊 ) ⟶ ( Base ‘ 𝑊 ) ) ) | 
						
							| 11 |  | eleq1 | ⊢ ( 𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  →  ( 𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) )  ↔  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) | 
						
							| 12 |  | fvex | ⊢ ( Base ‘ 𝑊 )  ∈  V | 
						
							| 13 | 12 12 | elmap | ⊢ ( ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) )  ↔  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) : ( Base ‘ 𝑊 ) ⟶ ( Base ‘ 𝑊 ) ) | 
						
							| 14 | 11 13 | bitr2di | ⊢ ( 𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  →  ( ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) : ( Base ‘ 𝑊 ) ⟶ ( Base ‘ 𝑊 )  ↔  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) | 
						
							| 15 | 14 | anbi2d | ⊢ ( 𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  →  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) : ( Base ‘ 𝑊 ) ⟶ ( Base ‘ 𝑊 ) )  ↔  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) ) | 
						
							| 16 | 10 15 | bitrid | ⊢ ( 𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) )  →  ( 𝑥  ∈  dom  𝐾  ↔  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) ) | 
						
							| 17 | 16 | pm5.32ri | ⊢ ( ( 𝑥  ∈  dom  𝐾  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ↔  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) ) | 
						
							| 18 |  | an32 | ⊢ ( ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ↔  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) | 
						
							| 19 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 20 | 19 | biantrur | ⊢ ( 𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) )  ↔  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) | 
						
							| 21 | 20 | anbi2i | ⊢ ( ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) )  ↔  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) ) | 
						
							| 22 | 17 18 21 | 3bitri | ⊢ ( ( 𝑥  ∈  dom  𝐾  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ↔  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) ) | 
						
							| 23 | 22 | opabbii | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  dom  𝐾  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) }  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) } | 
						
							| 24 |  | df-mpt | ⊢ ( 𝑥  ∈  dom  𝐾  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  dom  𝐾  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) } | 
						
							| 25 |  | inopab | ⊢ ( { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) }  ∩  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) } )  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  ∧  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) ) } | 
						
							| 26 | 23 24 25 | 3eqtr4i | ⊢ ( 𝑥  ∈  dom  𝐾  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) )  =  ( { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ( LSubSp ‘ 𝑊 )  ∧  𝑦  =  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) }  ∩  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  V  ∧  𝑦  ∈  ( ( Base ‘ 𝑊 )  ↑m  ( Base ‘ 𝑊 ) ) ) } ) | 
						
							| 27 | 6 9 26 | 3eqtr4i | ⊢ 𝐾  =  ( 𝑥  ∈  dom  𝐾  ↦  ( 𝑥 𝑃 (  ⊥  ‘ 𝑥 ) ) ) |