| Step | Hyp | Ref | Expression | 
						
							| 1 |  | inrab | ⊢ ( { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜑 }  ∩  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜓 } )  =  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  ( 𝜑  ∧  𝜓 ) } | 
						
							| 2 |  | diophin | ⊢ ( ( { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜑 }  ∈  ( Dioph ‘ 𝑁 )  ∧  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜓 }  ∈  ( Dioph ‘ 𝑁 ) )  →  ( { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜑 }  ∩  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜓 } )  ∈  ( Dioph ‘ 𝑁 ) ) | 
						
							| 3 | 1 2 | eqeltrrid | ⊢ ( ( { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜑 }  ∈  ( Dioph ‘ 𝑁 )  ∧  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  𝜓 }  ∈  ( Dioph ‘ 𝑁 ) )  →  { 𝑡  ∈  ( ℕ0  ↑m  ( 1 ... 𝑁 ) )  ∣  ( 𝜑  ∧  𝜓 ) }  ∈  ( Dioph ‘ 𝑁 ) ) |