| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pjpm.v | ⊢ 𝑉  =  ( Base ‘ 𝑊 ) | 
						
							| 2 |  | pjpm.l | ⊢ 𝐿  =  ( LSubSp ‘ 𝑊 ) | 
						
							| 3 |  | pjpm.k | ⊢ 𝐾  =  ( proj ‘ 𝑊 ) | 
						
							| 4 |  | eqid | ⊢ ( ocv ‘ 𝑊 )  =  ( ocv ‘ 𝑊 ) | 
						
							| 5 |  | eqid | ⊢ ( proj1 ‘ 𝑊 )  =  ( proj1 ‘ 𝑊 ) | 
						
							| 6 | 1 2 4 5 3 | pjfval | ⊢ 𝐾  =  ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) ) | 
						
							| 7 |  | inss1 | ⊢ ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) )  ⊆  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) | 
						
							| 8 | 6 7 | eqsstri | ⊢ 𝐾  ⊆  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) | 
						
							| 9 |  | funmpt | ⊢ Fun  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) | 
						
							| 10 |  | funss | ⊢ ( 𝐾  ⊆  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  →  ( Fun  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  →  Fun  𝐾 ) ) | 
						
							| 11 | 8 9 10 | mp2 | ⊢ Fun  𝐾 | 
						
							| 12 |  | eqid | ⊢ ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  =  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) | 
						
							| 13 |  | ovexd | ⊢ ( 𝑥  ∈  𝐿  →  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) )  ∈  V ) | 
						
							| 14 | 12 13 | fmpti | ⊢ ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) : 𝐿 ⟶ V | 
						
							| 15 |  | fssxp | ⊢ ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) ) : 𝐿 ⟶ V  →  ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ⊆  ( 𝐿  ×  V ) ) | 
						
							| 16 |  | ssrin | ⊢ ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ⊆  ( 𝐿  ×  V )  →  ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) )  ⊆  ( ( 𝐿  ×  V )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) ) ) | 
						
							| 17 | 14 15 16 | mp2b | ⊢ ( ( 𝑥  ∈  𝐿  ↦  ( 𝑥 ( proj1 ‘ 𝑊 ) ( ( ocv ‘ 𝑊 ) ‘ 𝑥 ) ) )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) )  ⊆  ( ( 𝐿  ×  V )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) ) | 
						
							| 18 | 6 17 | eqsstri | ⊢ 𝐾  ⊆  ( ( 𝐿  ×  V )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) ) | 
						
							| 19 |  | inxp | ⊢ ( ( 𝐿  ×  V )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) )  =  ( ( 𝐿  ∩  V )  ×  ( V  ∩  ( 𝑉  ↑m  𝑉 ) ) ) | 
						
							| 20 |  | inv1 | ⊢ ( 𝐿  ∩  V )  =  𝐿 | 
						
							| 21 |  | incom | ⊢ ( V  ∩  ( 𝑉  ↑m  𝑉 ) )  =  ( ( 𝑉  ↑m  𝑉 )  ∩  V ) | 
						
							| 22 |  | inv1 | ⊢ ( ( 𝑉  ↑m  𝑉 )  ∩  V )  =  ( 𝑉  ↑m  𝑉 ) | 
						
							| 23 | 21 22 | eqtri | ⊢ ( V  ∩  ( 𝑉  ↑m  𝑉 ) )  =  ( 𝑉  ↑m  𝑉 ) | 
						
							| 24 | 20 23 | xpeq12i | ⊢ ( ( 𝐿  ∩  V )  ×  ( V  ∩  ( 𝑉  ↑m  𝑉 ) ) )  =  ( 𝐿  ×  ( 𝑉  ↑m  𝑉 ) ) | 
						
							| 25 | 19 24 | eqtri | ⊢ ( ( 𝐿  ×  V )  ∩  ( V  ×  ( 𝑉  ↑m  𝑉 ) ) )  =  ( 𝐿  ×  ( 𝑉  ↑m  𝑉 ) ) | 
						
							| 26 | 18 25 | sseqtri | ⊢ 𝐾  ⊆  ( 𝐿  ×  ( 𝑉  ↑m  𝑉 ) ) | 
						
							| 27 |  | ovex | ⊢ ( 𝑉  ↑m  𝑉 )  ∈  V | 
						
							| 28 | 2 | fvexi | ⊢ 𝐿  ∈  V | 
						
							| 29 | 27 28 | elpm | ⊢ ( 𝐾  ∈  ( ( 𝑉  ↑m  𝑉 )  ↑pm  𝐿 )  ↔  ( Fun  𝐾  ∧  𝐾  ⊆  ( 𝐿  ×  ( 𝑉  ↑m  𝑉 ) ) ) ) | 
						
							| 30 | 11 26 29 | mpbir2an | ⊢ 𝐾  ∈  ( ( 𝑉  ↑m  𝑉 )  ↑pm  𝐿 ) |